A car travels at 54 km/h for first 20 s, 36 km/h for next 30 s and finally 18 km/h for next 10 s. Find its average speed.

1. DISAGREE: An RPE of 10 means the activity is extremely hard.
2. AGREE: Swimming and playing basketball are vigorous activities.
3. AGREE: Street and hip-hop dances are active recreational activities.
4. DISAGREE: Proper execution of dance steps reduces the risk of injuries.
5. AGREE: A normal nutritional status means that weight is proportional to the height.
6. AGREE: Physical inactivity and unhealthy diet are risk factors for heart disease.
7. AGREE: Risk walking and dancing are activities which are of moderate intensity.
8. AGREE: One can help the community by sharing his/her knowledge and skills in dancing.
9. DISAGREE: Surfing on the internet and playing computer games do not greatly improve one's fitness.
10. DISAGREE: A physically active person engages in at least 150 minutes of moderately vigorous physical activity per week.

Visit https://brainly.com/question/1133404 to know more about activities

#SPJ11

the charge is moving at a speed of 1.43 x 10^3 m/s.

To solve this problem, we can use the equation for the magnetic force on a moving charge:

F = qvB

where F is the force, q is the charge, v is the velocity, and B is the magnetic field.

Rearranging the equation to solve for velocity, we get:

v = F / (qB)

Plugging in the given values, we get:

v = (2.14 x 10^-8 N) / [(2.99 x 10^-6 C) x (5.00 x 10^-5 T)]

Simplifying, we get:

v = 1.43 x 10^3 m/s

Therefore, the charge is moving at a speed of 1.43 x 10^3 m/s.

Know more about Charge Particles and Magnetic Fields here:
https://brainly.com/question/15302071?referrer=searchResults

#SPJ11

Magnetic field is necessary for 1.0 [tex]m^{3}[/tex] of that field to contain 1.0 J of energy.

The energy density u of a magnetic field is given by

u = [tex]B^{2}[/tex]/(2μ)

Where B is the magnitude of the magnetic field and μ is the permeability of free space, which is a constant equal to 4π x [tex]10^{-7}[/tex] Tm/A.

If we want 1.0 [tex]m^{3}[/tex] of the magnetic field to contain 1.0 J of energy, we can rearrange the above equation to solve for B

Substituting the given values, we get

B =[tex]\sqrt{(2*4\pi *10^{-7}Tm/A*1 J/1m^{3 }[/tex]

B = 0.00224 T

Therefore, a magnetic field of 0.00224 T is necessary for 1.0 [tex]m^{3}[/tex] of that field to contain 1.0 J of energy.

To know more about Magnetic field here

https://brainly.com/question/17223673

#SPJ4

The work done by the weightlifter on the barbell is 166 J.

The work done on an object is given by the equation W = Fd, where W is the work done, F is the force applied, and d is the displacement of the object. In this case, the weightlifter is applying a force to lift the barbell against the force of gravity.

The weight of the barbell can be calculated as W = mg, where m is the mass of the barbell and g is the acceleration due to gravity (approximately 9.8 [tex]m/s^{2}[/tex]).

Substituting the values given, we get: W = (13.0 kg)(9.8 [tex]m/s^{2}[/tex]) = 127.4 N

To find the work done, we need to multiply the force by the distance moved, so: W = (127.4 N)(1.30 m) = 165.6 J

Therefore, the work done by the weightlifter on the barbell is 166 J (rounded to the nearest whole number).

To know more about gravity, refer here:

https://brainly.com/question/31321801#

#SPJ11

Answer:

When a pollen grain is placed in water, it may exhibit movement due to various factors such as osmosis, surface tension, and water absorption. The direction in which the pollen grain moves can depend on these factors and the specific characteristics of the pollen grain.

Osmosis: Osmosis is the movement of water molecules across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. If the pollen grain has a higher solute concentration than the surrounding water, water molecules will move into the pollen grain, causing it to swell or expand. This can result in movement towards areas of lower water concentration.

Surface Tension: Surface tension is the property of a liquid that allows it to resist external forces. The surface tension of water can cause the pollen grain to be pulled or dragged along the surface of the water, creating movement in a particular direction. This movement is influenced by the shape and weight distribution of the pollen grain.

Water Absorption: The outer covering of a pollen grain, called the exine, may have the ability to absorb water. As water is absorbed, the pollen grain can become hydrated and change in size and weight. This change in physical properties can lead to movement in a specific direction.

It's important to note that the direction of movement may not always be uniform or predictable, as it can be influenced by multiple factors and the unique characteristics of the pollen grain. Additionally, external factors such as water currents or agitation can also affect the movement of the pollen grain in water.

Observing the actual movement of a pollen grain in water would provide a more accurate understanding of its specific direction and behavior in that particular instance.

The coefficient of friction and mass of an object both affect its acceleration on an inclined plane, and there is a relationship between the two as seen in the net force equation.

The coefficient of friction is a measure of the amount of friction between two surfaces in contact. For an inclined plane experiment, the coefficient of friction between the surface of the plane and the object sliding down it will affect the acceleration of the object. Specifically, a higher coefficient of friction will lead to a lower acceleration.

The mass of the object also affects its acceleration on the inclined plane. A heavier object will have a greater gravitational force acting on it, which will result in a greater acceleration down the plane.

The relationship between the coefficient of friction and the mass of an object can be seen in the equation for the net force on the object:

[tex]Fnet = mgsin(\theta) - \mu\;mgcos(\theta),[/tex]

where μ is the coefficient of friction, m is the mass of the object, g is the acceleration due to gravity, and θ is the angle of the inclined plane.

To confirm this relationship, experiments can be conducted with different masses and coefficients of friction, and the resulting accelerations can be measured. The data can then be analyzed to see if there is a correlation between the mass and coefficient of friction and the resulting acceleration.

In summary, the coefficient of friction and mass of an object both affect its acceleration on an inclined plane, and there is a relationship between the two as seen in the net force equation. Experiments can be conducted to confirm this relationship.

To know more about mass refer here:

https://brainly.com/question/18064917#

#SPJ11

The total distance travelled by the car is 0.

The correct answer is (a).

Let the acceleration of the car be a and the time interval during which it accelerates be t1. During this time, the car travels a distance d1 given by:

[tex]d1 = (1/2)at1^2[/tex]

When the car reaches a speed of 0, it continues to move with uniform motion for another time interval t2. The distance travelled during this time is given by:

d2 = 0t2 = 0

The total distance travelled by the car is therefore:

[tex]d = d1 + d2 = (1/2)at1^2[/tex]

We need to eliminate the unknown time t1 in order to express the total distance travelled in terms of the acceleration a. We can do this by using the fact that the final speed of the car is 0:

v = at1 = 0

Therefore, the time interval t1 is:

t1 = 0

Substituting this into the expression for d, we get:

[tex]d = (1/2)at1^2 = 0[/tex]

To know more about distance refer here

https://brainly.com/question/31713805#

#SPJ11

A standing wave with two antinodes on a vibrating string represents the 1st overtone, which is also known as the 2nd harmonic. The wavelength is 148 cm. The 2nd harmonic already has two antinodes, so for the 3rd, 4th, and 5th harmonics, there will be 3, 4, and 5 antinodes, respectively.

(a) A standing wave with two antinodes on a vibrating string represents the 1st overtone, which is also known as the 2nd harmonic.
(b) To determine the wavelength of this wave, first, recall that the length of the string is half of the wavelength for the 2nd harmonic. So, we can use the following formula:
Length of the string = Wavelength / 2
Now, plug in the given values:
74 cm = Wavelength / 2
To find the wavelength, multiply both sides by 2:
Wavelength = 74 cm × 2 = 148 cm
(c) If the tension in the string is 20.0 N, first, we need to find the fundamental frequency. In a standing wave pattern with 1 antinode (1st harmonic), the length of the string is equal to half of the wavelength. So, the wavelength of the fundamental frequency is:
Wavelength (1st harmonic) = 2 ×  Length of the string = 2 ×  74 cm = 148 cm
To find the next three frequencies that could cause standing wave patterns on the string, we will look at the 3rd, 4th, and 5th harmonics. For each harmonic, the number of nodes increases by 1. The 2nd harmonic already has two antinodes, so for the 3rd, 4th, and 5th harmonics, there will be 3, 4, and 5 antinodes, respectively.

Learn more about antinodes here:-

https://brainly.com/question/30640087

#SPJ11

The force of gravity will be greater if one object has a larger mass than the other.

Gravity is the force of attraction between two objects with mass. According to Newton's law of gravitation, the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

F = G * (m₁ * m₂) / d²

where:

F = force of gravity

G = gravitational constant (a universal constant)

m₁, m₂ = masses of the two objects

d = distance between the two objects

As we can see from the formula, the force of gravity is directly proportional to the masses of the two objects. Therefore, if one object has a larger mass than the other, the force of gravity between them will be greater.

To know more about force, here

https://brainly.com/question/13191643

#SPJ4

The momentum of one 300-series Shinkansen train at its top speed of 270 km/h is 1.93 x[tex]10^{8}[/tex] kg*m/s.

Whast is Mass?

Mass is a fundamental physical property of matter that quantifies the amount of matter in an object. It is a scalar quantity that measures the resistance of an object to a change in its motion or acceleration, and is typically measured in units of kilograms (kg) in the International System of Units (SI).

The momentum (p) of an object can be calculated using the formula p = mv, where m is the mass of the object and v is its velocity. The mass of the 300-series Shinkansen train is given as 7.10 x [tex]10^{5}[/tex] kg. To calculate its momentum, we need to convert the velocity of 270 km/h to m/s. 270 km/h is equivalent to 75 m/s. Therefore, the momentum of one 300-series Shinkansen train at its top speed is:

p = mv = 7.10 x [tex]10^{5}[/tex] kg x 75 m/s = 1.93 x [tex]10^{8}[/tex] kg*m/s

Learn more about Mass from the given link

https://brainly.com/question/86444

#SPJ4

The unbalanced net force acting on the rope is 200 N to the left. This means that the rope will move in the direction of the net force, which is to the left.

The unbalanced net force is the overall force acting on the object after considering all the forces acting on it.

In this case, one person is pulling on a rope with a force of 400 N to the right and the other person is pulling on the opposite end with a force of 600 N to the left.

To determine the net force, we need to subtract the force acting in the opposite direction from the force acting in the forward direction.

Since the forces are in opposite directions, we need to subtract the smaller force from the larger force:

Net force = 600 N - 400 N = 200 N to the left

To know more about net force refer here

https://brainly.com/question/29261584#

#SPJ11

The normal force exerted on the crate by the elevator is 294 N. The normal force is the force exerted by a surface perpendicular to an object in contact with it.

In this case, the crate is in contact with the floor of the elevator. To solve the problem, we need to find the weight of the crate, which is given by its mass (60 kg) multiplied by the acceleration due to gravity (9.8 m/s2).

So the weight of the crate is 588 N. The force exerted on the crate by the elevator is the normal force.

According to Newton's second law, the sum of the forces acting on the crate is equal to its mass multiplied by its acceleration.

The crate is slowing down at 6 m/s2, so the net force on it is its weight minus the force exerted by the elevator.

Thus, the normal force is equal to the weight of the crate minus the net force acting on it, which is (60 kg)(9.8 m/s2) - (60 kg)(6 m/s2) = 294 N. Therefore, the normal force exerted on the crate by the elevator is 294 N.

To know more about Newton's second law, refer here:

https://brainly.com/question/13447525#

#SPJ11

To describe the graph we need to explain the specific concepts mentioned below:

a. The relationship between variables on a graph refers to how one variable changes in response to the other. This can be positive (both variables increase or decrease together), negative (one variable increases while the other decreases), or no relationship (no discernible pattern between the two variables).

b. A graph can be classified as linear or nonlinear based on the shape of the relationship between the variables. A linear graph forms a straight line, indicating a constant rate of change between the variables. A nonlinear graph has a curve or irregular shape, indicating a variable rate of change between the variables.

c. An example of a graph could be a scatter plot of people's ages (x-axis) and their monthly income (y-axis). If the points form a straight line with a positive slope, it would indicate a linear relationship, meaning that as people's ages increase, their income generally increases as well.

For more questions on: concepts

https://brainly.com/question/18798678

#SPJ11

In physics, we use vector addition to calculate the net force direction when more than one force is applied. Given the separate x and y components of two forces, F₁ and F₂, we sum the components respectively to find the x and y components of the net force. The arctangent of the ratio Fy/Fₓ then gives the direction in degrees relative to the x-axis.

In physics, specifically in mechanics, you can calculate the net force direction when two forces, F₁ and F₂, are being applied by using vector addition. Vector addition can be visualized graphically using arrows or mathematically using components. In this case, since the forces are given in the form of components (x and y), let's handle it mathematically, the x-component of the net force (Fₓ) will be the sum of the x-components of F₁ and F₂. Similarly, the y-component of the net force (Fy) will be the sum of the y-components of F₁ and F₂. This gives us Fₓ = 5.01N + 3.01N and Fy = 3.0N + 2.0N. The direction of the net force can then be calculated using arctangent of the ratio Fy/Fₓ. This will give the direction in degrees relative to the x-axis.

https://brainly.com/question/26066229

#SPJ1

The rest energy of a silver atom can be calculated using Einstein's famous equation, E=[tex]mc^{2}[/tex], where E is the energy, m is the mass and c is the speed of light.

Rest energy of a silver atom (E) = mass of silver atom (m) x speed of light [tex](c)^{2}[/tex]

= 1.8 x [tex]10^{-25}[/tex] kg x (3 x [tex]10^{8}[/tex] [tex]m/s)^{2}[/tex]

= 1.62 x [tex]10^{8}[/tex] J

This means that even when the silver atom is at rest, it has an enormous amount of energy stored in its mass due to its mass-energy equivalence.

This concept is important in understanding nuclear reactions, where a small amount of mass is converted into energy through the process of nuclear fission or fusion.

To know more about Einstein, refer here:

https://brainly.com/question/31320432#

#SPJ11

Her pace at 10 seconds is 1 m/s. We can solve this problem by using the equations of motion for constant acceleration.

First, we need to find Selina's velocity at 10 seconds. We can do this by using the equation: v = u + at, where v is the final velocity, u is the initial velocity (which is zero in this case), a is the acceleration, and t is the time.

Plugging in the values, we get: v = 0 + (0.1 m/s^2) x (10 s), v = 1 m/s

So Selina's velocity at 10 seconds is 1 m/s.

Next, we can find her pace (or speed) by dividing the distance she has traveled by the time taken.

Since we don't know the distance she has traveled, we'll assume that she has covered the same distance as she would have if she had maintained a constant speed of 1 m/s for the entire 10 seconds.

So the distance traveled, d, is: d = v x t, d = (1 m/s) x (10 s), d = 10 m

Therefore, Selina's pace at 10 seconds is: pace = distance / time, pace = 10 m / 10 s, pace = 1 m/s. So her pace at 10 seconds is 1 m/s.

To know more about equations of motion, refer here:

https://brainly.com/question/31062885#

#SPJ11

The force exerted on the 0.04 kg arrow, which accelerated at 7,000 m/s² to reach a speed of 60.0 m/s, is 280 N.

To calculate the force exerted on the arrow, we can use Newton's second law of motion, which states that the force acting on an object is equal to its mass multiplied by its acceleration (F = m*a). In this case, the mass of the arrow (m) is 0.04 kg, and its acceleration (a) is 7,000 m/s².

Step 1: Identify the mass (m) and acceleration (a) of the arrow.
m = 0.04 kg
a = 7,000 m/s²

Step 2: Apply Newton's second law of motion (F = m*a) to calculate the force (F).
F = 0.04 kg * 7,000 m/s²

Step 3: Multiply the mass and acceleration values to obtain the force.
F = 280 N

Therefore, the force exerted on the arrow is 280 Newtons.

Know more about Newton's second law of motion click here:

https://brainly.com/question/27712854

#SPJ11

The escape velocity of the planet is roughly 0.707 times that of the Earth.

To get escape velocity, multiply 2 x G x M, divide the result by r, and then take the square root of the answer. In this equation, G stands for Newton's gravitational constant, M for the planet's mass in kilogrammes, and r for the planet's radius in metres.

v = √(2GM/r)

where M is the planet's mass, v is the escape velocity, G is the gravitational constant, and r is the planet's radius.

In this case, the planet has twice the mass of the Earth (2M) and eight times the radius of the Earth (8R).

v = √(2G(2M)/(8R))

Simplifying this expression, we get:

v = √(1/2) * √(GM/R)

Since GM/R is a constant for any planet, we can see that the escape velocity of this planet is equal to the escape velocity of Earth multiplied by √(1/2), which is approximately 0.707.

To know more about velocity visit:-

https://brainly.com/question/17127206

#SPJ1

The angular speed of the sphere at the bottom of the ramp is approximately 7.64 rad/s.

We can use the conservation of energy principle. The total mechanical energy of the system (kinetic energy + potential energy) will be conserved, assuming there is no friction.

1. Find the potential energy of the sphere at the top of the ramp:

U = mgh

where m = 200 N, g = [tex]9.8 m/s^2[/tex], and h = d*sin(θ)

h = 6.0 m * sin(34°) = 3.40 m

U = (200 N)*([tex]9.8 m/s^2[/tex])*(3.40 m) = 6616 J

2. Find the kinetic energy of the sphere at the bottom of the ramp:

[tex]K = (1/2)*I*w^2 + (1/2)*mv^2[/tex]

where I is the moment of inertia of the sphere, w is the angular speed, and v is the linear speed of the sphere.

Since the sphere is rolling without slipping, we can use the relationship between linear and angular speed:

v = r*w

Also, for a solid sphere, the moment of inertia is I = (2/5)*m*r^2.

Substituting these values, we get:

[tex]K = (1/2)*(2/5)*m*r^2*w^2 + (1/2)*mv^2[/tex]

[tex]K = (1/5)*m*r^2*w^2 + (1/2)*mv^2[/tex]

At the bottom of the ramp, the sphere has no initial linear or angular speed, so v = 0.

3. Equate the initial and final energies to find the final angular speed:

K + U = U_f

where U_f = 0 (since the sphere has reached the bottom of the ramp and has no potential energy).

Substituting the values of K and U, we get:

[tex](1/5)*m*r^2*w^2 = -U[/tex]

[tex](1/5)*200 N*(0.20 m)^2*w^2 = -6616 J[/tex]

Solving for w, we get:

[tex]w = \sqrt{(-5*6616 J / (2*200 N*(0.20 m)^2))}[/tex]

w ≈ 7.64 rad/s

To know more about energy refer here

https://brainly.com/question/41687426#

#SPJ11

There are 0.506 grams in 0.02 moles of Mg

To find the grams of Mg in 0.02 mol, you can use the formula:

grams = moles × molar mass

In this case, moles = 0.02 mol, and the molar mass of Mg = 25.3 g/mol. Plug in the values:

grams = 0.02 mol × 25.3 g/mol

grams = 0.506 g

So, there are 0.506 grams of Mg in 0.02 mol.

Visit https://brainly.com/question/31597231 to learn more about moles

#SPJ11

The farthest bright galaxies that modern telescopes are currently capable of seeing are up to several billions of light-years away. The exact distance depends on various factors such as the sensitivity and resolution of the telescope, observational techniques, and the brightness of the galaxy itself.

Modern telescopes, such as the Hubble Space Telescope and large ground-based observatories equipped with advanced instruments, have greatly advanced our ability to observe and study distant galaxies. These telescopes can detect and capture the light from galaxies that existed when the universe was relatively young.

Through deep field observations and gravitational lensing techniques, astronomers have been able to observe galaxies that are more than 13 billion light-years away. These observations provide valuable insights into the early universe and its evolution.

It's important to note that the term "bright" is relative and can vary depending on the context and specific criteria used for brightness. Additionally, ongoing advancements in telescope technology continue to push the limits of observation, and future telescopes and space missions are expected to enable us to see even farther into the universe.

To know more about  telescopes refer here

https://brainly.com/question/19349900#

#SPJ11

At a height of 6.37 10⁶ meters above the Earth's surface, the astronaut's weight is 195.5 N.

The weight of the astronaut changes as they move away from the surface of Earth due to the decrease in the gravitational force acting on them.

Use the formula:

F = Gm₁m₂/r²

where F = gravitational force,

G = gravitational constant,

m₁ = mass of the Earth,

m₂ = mass of the astronaut, and

r = distance between the center of the Earth and the astronaut.

Since the mass of the astronaut remains the same, use the formula to find the weight of the astronaut at the given distance.

First, calculate the distance from the center of the Earth to the astronaut:

r = radius of the Earth + height above the surface

r = 6,371,000 m + 6,370,000 m = 12,741,000 m

Calculate the gravitational force acting on the astronaut:

F = Gm₁m₂/r²

F = (6.6743 × 10⁻¹¹ N m²/kg²) x (5.972 × 10²⁴ kg) x (80 kg) / (12,741,000 m)²

F = 195.5 N

Therefore, the weight of the astronaut at a height of 6.37 × 10⁶meters above the surface of Earth is 195.5 N.

Find out more on astronaut weight here: https://brainly.com/question/4080619

#SPJ1

The angle of the incline is approximately 56.9 degrees.

To determine the angle of the incline, we need to use some basic physics equations related to work, power, and energy.

Firstly, we know that the box is moving up the incline at a constant speed, which means that the net force acting on it must be zero. Since there is no friction, the only force acting on the box is its weight, which is given by:

F = m * g

Where F is the force, m is the mass of the box, and g is the acceleration due to gravity. Substituting the given values, we get:

F = 1000 kg * 9.8 m/s^2

= 9800 N

Next, we need to determine the work done by the motor to move the box up the incline. Since the box is moving at a constant speed, the work done must be equal to the power supplied by the motor multiplied by the time taken. Using the given values, we get:

Work = Power * Time

Work = 30 W * 3600 s

= 108000 J

Finally, we can use the concept of potential energy to relate the work done to the change in height of the box. The potential energy of an object is given by:

PE = m * g * h

Where PE is the potential energy, h is the height above some reference level, and all other variables are as defined above. Since the box is moving up a frictionless incline, its potential energy is increasing by an amount equal to the work done by the motor. Thus, we have:

Work = PE_final - PE_initial

PE_final = m * g * h_final

PE_initial = m * g * h_initial

Substituting the given values, we get:

108000 J = 1000 kg * 9.8 m/s^2 * (h_final - h_initial)

Since the box is moving up the incline, its final height must be greater than its initial height. Dividing both sides by 1000 * 9.8, we get:

h_final - h_initial = 11.02 m

Now, we can use trigonometry to relate the height difference to the angle of the incline. Since the box is moving a horizontal distance of 13 m, we have:

sin(theta) = (h_final - h_initial) / 13

sin(theta) = 11.02 / 13

theta = sin^-1(11.02 / 13)

theta = 56.9 degrees (rounded to one decimal place)

Therefore, the angle of the incline is approximately 56.9 degrees.

For such more question on net force

https://brainly.com/question/14361879

#SPJ11

According to the theory of special relativity, the speed of light is constant in all inertial frames of reference. Therefore, the speed of the pulses of light measured by the spaceship will be the same as the speed of light, c.

However, since the spaceship is moving towards the distant star at 0.90c, the relative speed of the spaceship with respect to the pulses of light will be c - 0.90c = 0.10c. This means that the pulses of light will approach the spaceship at a speed of 0.10c.

To understand this concept more clearly, imagine you are standing still and someone throws a ball towards you at 10 mph. The relative speed of the ball with respect to you is 10 mph. Now, if you start walking towards the ball at 5 mph, the relative speed of the ball with respect to you will be 10 mph - 5 mph = 5 mph. Similarly, in the case of the spaceship, the relative speed of the pulses of light with respect to the spaceship will decrease as the spaceship moves towards the source of the light.

In conclusion, the pulses of light will approach the spaceship at a speed of 0.10c from the spaceship's point of view. This concept is important in understanding the effects of relative motion on the measurement of physical phenomena, and it has implications for our understanding of the nature of space and time.

To know more about special relativity refer here

https://brainly.com/question/12717449#

#SPJ11

Since the force is zero, the boat does not move. Therefore, the distance the boat moves away from the pier as Jake walks to the front of the boat is zero.  

To solve this problem, we need to use the conservation of linear momentum.

The total mass of the boat and the two brothers is given by:

M = m_boat + m_brother_1 + m_brother_2

= 83.0 kg + 59.5 kg + 50.0 kg

= 192.5 kg

The total momentum of the system before Jake starts walking is given by:

P_total = m_boat * v_boat + m_brother_1 * v_brother_1 + m_brother_2 * v_brother_2

= (83.0 kg) * (v_boat) + (59.5 kg) * (0) + (50.0 kg) * (0)

= 83.0 kg * v_boat + 297.5 kg * 0

= 210.5 kg * v_boat

v_boat is the velocity of the boat, measured in the same direction as the displacement of the boat.

Since the boat is stationary initially, v_boat = 0.

Now, we can apply Newton's second law to the system. The force exerted on the boat by Jake, who is walking towards the front of the boat, is equal to the momentum of the boat relative to Jake. Since Jake is walking away from the pier, the momentum of the boat relative to Jake is negative. Therefore, we have:

F = P_relative - P_initial

= -210.5 kg * v_boat - 297.5 kg * 0

= -408.0 kg * 0

= 0 N

Learn more about force Visit: brainly.com/question/30236242

#SPJ4

The electric field of a 460 MHz radio wave with a maximum rate of change 4.5 × 1011 (v/m)/s. The wave's magnetic field amplitude is [tex]1.5 \times 10^{-3} T[/tex].

To determine the magnetic field amplitude of a 460 MHz radio wave with a maximum rate of change of the electric field, we can use the relationship between the electric and magnetic fields in electromagnetic waves.

The electric and magnetic fields are perpendicular to each other and travel at the speed of light. The magnetic field amplitude can be calculated using the formula:

B = E / c

Where B is the magnetic field amplitude, E is the maximum rate of change of the electric field, and c is the speed of light.

Substituting the given values, we get:

[tex]B = (4.5 \times 10^{11} V/m/s) / (3 \times 10^8 m/s)[/tex]

[tex]B = 1.5 \times 10^{-3} T[/tex]

Therefore, the magnetic field amplitude of the radio wave is [tex]1.5 \times 10^{-3} T.[/tex]

In summary, the magnetic field amplitude of a 460 MHz radio wave with a maximum rate of change of the electric field can be calculated using the relationship between the electric and magnetic fields in electromagnetic waves.

To know more about electric field refer here:

https://brainly.com/question/27897603?#

#SPJ11

Answer:

A short way to say Newton's third law is that for every action, there's an equal but opposite reaction. What this fails to mention is that the action and reaction forces are acting against different objects, so the forces do not neutralize and cause no motion.

When you write, you push the pen on the paper; the pen is pushing the paper. Meanwhile, the paper is pushing back on the pen in equal magnitude. The forces balance making the paper stay in place. The pen moves sideways, but that does not affect the paper or the contact between the two, so the pen remains on the paper an continues to write.

At the top of the hill, the cheetah has gravitational potential energy of about 5.02 joules. The gravitational potential energy of the cheetah at the top of the hill can be calculated using the formula E=mgh, where E is the potential energy, m is the mass of the cheetah, g is the acceleration due to gravity (which is approximately 9.8 m/s^2), and h is the height of the hill.

Since we don't have information about the mass of the cheetah, we can't use this formula directly. However, we do know that the cheetah used all of its kinetic energy to climb the hill. So, we can use the fact that the work done by the cheetah to climb the hill (which is equal to its initial kinetic energy) is equal to the change in gravitational potential energy:

W = ΔE

where W is the work done and ΔE is the change in energy.

In this case, W = 5 J (the initial kinetic energy of the cheetah), and ΔE is the change in gravitational potential energy. Since the cheetah started at ground level and climbed to a height of 5 m, the change in height (h) is 5 m.

So, we can calculate the gravitational potential energy of the cheetah as:

ΔE = mgh

5 J = m(9.8 m/s^2)(5 m)

Solving for m, we get:

m = 0.102 kg

Now that we know the mass of the cheetah, we can use the formula E=mgh to calculate the gravitational potential energy:

E = (0.102 kg)(9.8 m/s^2)(5 m)

E = 5.02 J

Therefore, the gravitational potential energy of the cheetah at the top of the hill is approximately 5.02 joules.

Know more about gravitational potential energy here:

https://brainly.com/question/3884855

#SPJ11

The weight of the astronaut 6.37 × 106 meters above the surface of the Earth would be 160 N.

The weight of an object depends on its mass and the gravitational field it is in. Near the surface of the Earth, the acceleration due to gravity is approximately 9.81 m/s².

We can use the formula F = mg to calculate the weight of the astronaut at the surface of the Earth:

The gravitational field weakens as the distance from the center of the Earth increases, thus, we can use the formula for gravitational acceleration at a distance r from the center of the Earth:

Now we can calculate the weight of the astronaut at this height:

We don't know the mass of the astronaut, but we can use the weight at the surface of the Earth to find it:

         = 8.00 × 102 N / 9.81 m/s²

        = 81.63 kg

F' = (81.63 kg) x (1.96 m/s²)

F' = 160 N

Therefore, the weight of the astronaut 6.37 × 106 meters above the surface of the Earth is approximately 160 N.

More on the weight of Astronauts can be found here: https://brainly.com/question/11244838

#SPJ1