Postive and negatives attract, positive and positive repel. answer is negatively charged pipe.
sound waves and light energy are not "affected" by static electricity
An astronaut named Sandra Bullock has drifted too far away from her spaceshuttle while attempting to repair the Hubble Space telescope. She realizes that theshuttle is moving away from her at 3 m/s. On her back is a 10 kg jetpack which consistsof an 8 kg holding tank filled with 2 kg of pressurized gas. Without the jetpack, sheand her space suit have a mass of 80 kg.
Required:
a. She is able to use the gas to propel herself in the same direction as the shuttle. The gas exits the tank at a uniform rate with a constant velocity of 100 m/s, relative to the tank (and her). After the gas in the tank has been released, what is her velocity?
b. After this, she throws her empty tank into space and relies on the conservation of momentum to increase her speed to match that of the shuttle. With what velocity (in her frame of reference!) will she have to throw the tank?
Answer:
a) v_f = 0.898 m / s, b) v₂ = -6.286 m / s
Explanation:
a) For this exercise we use the conservation of momentum, we define a system formed by the astronaut, her equipment and the expelled gases. We must also define a stationary frame of reference, let's place the system on the platform, so the speed of the subject is v = -3 m / s
Initial instant. Before you start to pass gas
p₀ = (M + Δm) v
M is the mass of the astronaut M = 80Kg and Δm the masses of the gases
Final moment. When you expel the gases
p_f = M (v + Δv) + Δm (v-v_e)
where v_e is the gas velocity v_e = 100 m / s
momentum is conserved
p₀ = p_f
M v + Δm v = Mv + M Δv + Δm v -Δm ve
0 = M Δv - Δm v_e
if we make the very small quantities Δv → dv and Δm → dm, furthermore the quantity of output gas is equal to the decrease in the total mass dm = -dM
M dv = -v_e dM
∫ dv = - v_e ∫ dM / M
We solve, between the lower limits v₀ = v with M = M₀ and the upper limit v = v_f for M = M_f
v_f - v₀ = - v_e (ln M_f - Ln M₀)
v_f - v₀ = v_e ln ([tex]\frac{M_o}{M_f}[/tex])
v_f = v₀ + v_e ln (\frac{M_o}{M_f})
let's calculate
v_f = -1.3 + 100 ln (80 + 10 + 2/80 + 10)
v_f = -1.3 +2.20
v_f = 0.898 m / s
b) launch the jetpack to increase its speed up to the speed of the platform
initial instant. Before launching the tanks
p₀ = (M + m') v_f
final instnte. After launching the tanks
p_f = M v₁ + m' v₂
indicate that the final velocity of the astronaut is the platform velocity v₁=0 m / s, since the reference system is fixed on it
p₀ = p_f
(M+ m) v_f = M v₁ + m v₂2
v₂ = [tex]\frac{ M ( v_f - v_o) + m' v_f}{m'}[/tex]
v₂ = [tex]\frac{M}{m}[/tex] (v_f -v₁) + v_f
let's calculate
v₂ = 80/10 (0.898 - 0) + 0.898
v₂ = -7.1874 + 0.898
v₂ = -6.286 m / s
A cyclist cover 6km in 20minutes. His speed is
Answer:
The speed of a cyclist is 0.3 km/min.
Explanation:
Given
The distance d = 6km Time t = 20 minutesTo determine
We need to determine the speed of a cyclist.
In order to determine the speed of a cyclist, all we need to do is to divide the distance covered by a cyclist by the time taken to cover the distance.
We know the formula involving speed, time, and distance
[tex]s=\frac{d}{t}[/tex]
where
s = speedd = distance coveredt = time takensubstitute d = 6, and t = 20 in the formula
[tex]s=\frac{d}{t}[/tex]
[tex]s=\frac{6}{20}[/tex]
Cancel the common factor 2
[tex]s=\frac{3}{10}[/tex]
[tex]s=0.3[/tex] km/min
Thus, the speed of a cyclist is 0.3 km/min.
A radio transmitting station operating at a frequency of 125 MHz has two identical antennas that radiate in phase. Antenna B is 9.05 m to the right of antenna A. Consider point P between the antennas and along the line connecting them, a horizontal distance x to the right of antenna A. For what values of x will constructive interference occur at point P?
Answer:
Explanation:
The formula for frequency is:
[tex]f = \dfrac{c}{\lambda}[/tex]
If we make [tex]\lambda[/tex] the subject; we have:
[tex]\lambda = \dfrac{c}{f}[/tex]
[tex]\lambda = \dfrac{3\times 10^6 \ m/s}{125 \ MHz (\dfrac{10^6 \ Hz}{1 \ MHz})}[/tex]
[tex]\lambda = 2.4 \ m[/tex]
Let assume that there is a point P between antenna A to B.
where;
A to B = 9.05
A to P = x and
P to B = 9.05 - x
Then, the condition for the constructive inteference is:
Δx = nλ
x - (9.05 - x) = nλ
2x - 9.05 = n(2.4)
So, we need to start assigning values to n so that the value of x becomes less than or equal to 9.05 m
If n = -1
Then;
2x - 9.05 = (-1)(2.4)
x = 3.325 m
If n = -2
Then;
2x - 9.05 = (-2)(2.4)
x = 2.125 m
If n = -3
Then;
2x - 9.05 = (-3)(2.4)
x = 0.925 m
If n = 0
Then;
2x - 9.05 = (0)(2.4)
x = 4.525 m
If n = 1
2x - 9.05 = (1)(2.4)
x = 5.725 m
If n = 2
Then;
2x - 9.05 = (2)(2.4)
x = 6.925 m
Hence, there exist 7 points in which constructive interference occurs.
For a given substance, the molecules
move fastest when the substance is
Answer:GAS
Explanation:
A motorcycle and rider have a total mass equal to 300 kg. The rider applies the brakes, causing the motorcycle to decelerate at a rate of -5 m/s^2. What is the net force on the motorcycle?
Answer:
Net force = - 1500 N
Explanation:
We calculate the net force acting using Newton's second Law:
[tex]F_{net}=m*a\\F_{net}=(300 \,kg)*(-5\,m/s^2)\\F_{net}=-1500\,N[/tex]
3. Two cyclists that are 500 m apart start biking toward each other. They bike at speeds of 6 and
4 m/s.
How long does it take for them to reach each other?
a.
b. How far does the slower biker travel?
Answer:
A) 50 seconds
B) 200 m
Explanation:
They are 500 metres apart.
And one of the bike loves at 6 m/s while the other loves at 4 m/s.
A) Let distance of the 6 m/s bike before they meet be x.
Thus, time = x/6
Since time = distance/speed
For the second bike at 4 m/s, his distance covered before they meet will be 500 - x
Thus, time = (500 - x)/4
Now they will meet each other at the same time. Thus;
x/6 = (500 - x)/4
Cross multiply to get;
4x = 3000 - 6x
6x + 4x = 3000
10x = 3000
x = 3000/10
x = 300 m
Thus, time will be;
t = 300/6
t = 50 seconds
B) Distance covered by the slower bike is (500 - x)
Since from a above, x = 300
Thus; distance = 500 - 300 = 200 m
What is the acceleration of a .3 kg mass when there is a net force of 25.9 N on it?
Answer:
86.33m/s^2
Explanation:
Acceleration = Force/Mass
= 25.9/0.3
= 86.33
On Earth, the number flux of solar neutrinos from the p-p chain is:
f_neutrino = 2fo/2.62MeV
Other nuclear reactions in the Sun supplement this neutrino flux with a small additional flux of higher-energy neutrinos. A neutrino detector in Japan, named SuperKamiokande, consists of a tank of 50 kton of water, surrounded by photomultiplier tubes. The tubes detect the flash of Cerenkov radiation emitted by a recoiling electron when a high-energy neutrino scatters on it.
Required:
a. How many electrons are there in the water of the detector?
b. Calculate the detection rate for neutrino scattering, in events per day.
Answer:
Explanation:
The volume of the tank = 50 kton
50 kton = 5 × 10⁷ kg
Since 18 grams of water will contain: 10 electrons × 6.023 × 10²³
Then;
5× 10⁷ kg will contain [tex]( \dfrac{5 \times 10^7 \times 10^3}{18}) \times 10 \times 6.023 \times 10^{23}[/tex]
= 1.67 × 10³⁴ electrons
(b)
Suppose:
[tex]f_{neutrino} = \dfrac{2f_o}{26.2 MeV} = 6.7\times 10^{10} \ s^{-1} cm^{-2}[/tex]
Then;
10⁻⁶ of [tex]f_{neutrino} = 6.7 \times 10^{10} \times 10^{-6} \ s^{-1} cm^{-2}[/tex]
[tex]=6.7 \times 10^{4}\ s^{-1} cm^{-2}[/tex]
Thus, the number of high energy neutrinos which will interact with water is:
= [tex]6.7 \times 10^4 \times \sigma[/tex]
= [tex]6.7 \times 10^4 \times 10^{-43}[/tex]
= [tex]6.7 \times 10^{-39} s^{-1}[/tex]
For 1.67 × 10³⁴ electrons, the detection rate is:
[tex]6.7 \times 10^{-39} \times 1.67 \times 10^{34}[/tex]
[tex]= 11.19 \times 10^{-5} \ s^{-1}[/tex]
= 9.668 per day
Which of the following statements is true?
A. Friction primarily affects objects that contain iron.
B. Friction pulls objects toward the center of the Earth
C.
Friction does not affect objects in motion.
D.
Friction slows down or stops objects in motion.
Answer:
D. Friction slow down or stop objects in motion.
Four-wheel drive trucks do not stop better on icy
roads than a car. Is what law of motion (Newton's laws)
attraction is seen between the poles of two bar magnet in the case of
Answer:
he magnetic field of a bar magnet is strongest at either pole of the magnet. It is equally strong at the north pole when compared with the south pole. The force is weaker in the middle of the magnet and halfway between the pole and the centerExplanation:
HELP ITS FOR SCIENCE
1. Explain why a wrecking ball can destroy a building, but a yo-yo can’t. Use the term kinetic energy in your explanation.
2. How is speed related to kinetic energy?
Answer:
A wrecking ball has the capability to destroy a building due to the greater mass and kinetic energy than the yo-yo.
Work is a measurement of the transfer of which of the following?
A. Impulse
B. Power
C. Energy
Answer:Enegry
Explanation:Energy transfer is used to do work
The string will break if the tension in
it exceeds 0.180 N. What is the
smallest possible value of d (in cm)
before the string breaks?
Answer:
define d first?
you need to list more variables
Answer:
list more valuable unit
Can someone help please
Answer:
The average blood speed is 0.39 m/s
Explanation:
According to Poiseuille’s law, the volume flow rate, Q (m³/s) of a fluid of
viscosity η through a tube or pipe of radius r and length L is:
Q = πr⁴ΔP/8ηL
where ΔP is the change in pressure or pressure difference of the fluid; L is length of the pipe
Also, the volume flow rate, Q, is related to the average velocity v, by the formula:
Q = Av
where A is the cross-sectional area of the pipe; A = πr²
Q = πr²v
Thus, the Poiseuille’s becomes: πr²v = πr⁴ΔP/8ηL
v = r²ΔP/8ηL
From the given values:
r = 2.5 mm = 0.0025 m
L = 15 cm = 0.15 m
ΔP = 380 Pa
η = 5 * 10⁻³ Pa.s
substituting the given values in the equation
v = {(0.0025)² * 380} / (8 * 5 * 10⁻³ * 0.15)
v = 0.39 m/s
Therefore, the average blood speed is 0.39 m/s
a passenger on cruise between San Juan, Puerto Rico and Miami, Florida accidentally drops a souvenir metal cube over the side of the boat, into the water. Each side of the metal cube measures 1 meter. The cube promptly sinks to the deepest part of the Puero Rico Trench. Once at the bottom, what pressure does the cube experience? Neglect Atmospheric Pressure. Use wikipedia to see depth of Trench!
Answer:
P = 84.1 MPa
Explanation:
The pressure at the bottom of column of of salt water of height h, is given by the following expression:[tex]P = \rho * g * h (1)[/tex]
where ρ = density of salt water (in Kg/m³),
g = acceleration due to gravity (in m/s²)
h = height of the column of water.
Replacing by their values in (1):[tex]P = \rho * g * h = 1023.6kg/m3*9.8m/s2*8380m = 84.1 MPa (2)[/tex]
Neglecting the atmospheric pressure, the pressure on the cube at the bottom of Puerto Rico Trench is given by (2):P = 84.1 MPa.it is an organic compound and an essential micronutrient that the body needs in small amounts.
Answer:
Nutrients the body needs in relatively small amounts are called micronutrients. They include vitamins and minerals. Vitamins are organic compounds that are needed by the body to function properly. ... Vitamins and minerals do not provide energy, but they are still essential for good health
Explanation:
QUESTION 9 / 10
What is the first step you should take when you want to open a savings account?
A. Present your photo ID to the bank representative,
B. Make your initial deposit.
C. Review the different savings account options that your
bank offers.
D. Go to the bank and fill out an application.
Answer:
A
Explanation:
AWNSER:
awnser:
C
explanation:
Diagram B D c с Which car has: Ke = 100 PE=0? * 1 point A B C D
Answer:
The car C has KE = 100, PE = 0
Explanation:
The principle of conservation of energy states that although energy can be transformed from one form to another, the total energy of the given system remains unchanged.
The energy that a body possesses due to its motion or position is known as mechanical energy. There are two kinds of mechanical energy: kinetic energy, KE and potential energy, PE.
Kinetic energy is the energy that a body possesses due to its motion.
Potential energy is the energy a body possesses due to its position.
From the principle of conservation of energy, kinetic energy can be transformed into potential energy and vice versa, but in all cases the energy is conserved or constant.
In the diagram above, the cars at various positions of rest or motion are transforming the various forms of mechanical energy, but the total energy is conserved at every point. At the point A, energy is all potential, at B, it is partly potential partly kinetic energy, However, at the point C, all the potential energy has been converted to kinetic energy. At D, some of the kinetic energy has been converted to potential energy as the car climbs up the hill.
Therefore, the car C has KE = 100, PE = 0
how is work and energy inter-related?? (in simple words)
Answer:
The work and energy is inter- related because if we are energetic then only we are able to work.
People who are weak and not energetic cannot work continuously.
Explanation:
hope this helps you....
Matter is made of small particles to small to be seen. Which of these best describe evidence of this statement? 1. Tara’s crayons melted when she left them under the sun. 2. Kerris glass of water overflowed when she added ice. 3. Sams basketball expands as he pumps air into it. 4. Stephanie dropped a vase and it broke into pieces.
Answer:
Explanation:
I think the answer is statement no 3.
Hope it helps.
Answer:
1 Tara's crayons melted when she left them under the sun
What is the difference between the reflection and refraction of light
Answer:
Reflection can simply be defined as the reflection of light when it strikes the medium on a plane. Refraction can be defined as the process of the shift of light when it passes through a medium leading to the bending of light. The light entering the medium returns to the same direction.
Answer:
reflection is your image and refraction is light
Which statement accurately describes a relationship between parts of the
universe?
O A. There are millions of nebulae in a star.
O B. There are thousands of universes in a galaxy.
C. There are trillions of galaxies in the universe.
O D. There are billions of galaxies in a solar system.
Answer:
C. There are trillions of galaxies in the universe.
Explanation:
A. is wrong as nebulae are found inside galaxies and inside the universe, not inside stars.
B. is wrong because there are trillions of galaxies in the universe, not the latter.
D. The solar system consists of the eight planets, the Sun, comets, meteors, dwarf planets, and is inside the Milky Way galaxy and thus cannot have galaxies inside it.
Please give Brainliest
Answer:
C.
Explanation:
There are trillions of galaxies in the universe.
You are driving a car behind a truck. Both your car and the truck are moving at a speed of 80km/hr. If the driver of the truck suddenly slams on the brakes, what minimum distance betweenyour car and the truck is needed so that your car does not crash into the truck’s rear end? (This is called the "​minimum trailing distance​".) To simplify this problem, assume that the truck andthe car have the same braking acceleration.
a. In order to simplify the calculations for this problem, you are told to assume that the braking acceleration of the car and the truck are the same. What other reasonable assumptions do you need to make in order to solve this problem?
b. For both the truck and the car, draw an acceleration- and velocity-versus-time graph.
c. Find an expression for the minimum trailing distance. (Your expression should only contain symbols of physical quantities. No numbers are needed here.)
d. Find the numerical value for the minimum trailing distance (Plug the values of physical quantities into your expression from part A (do not forget units!))
Answer:
Explanation:
Let the velocity of car and truck be u and breaking acceleration be a .
We shall have to assume the reflex time of the driver of the car . By the time he applies brake , his car will cover some distance . There will be some time tag between the time the truck starts decelerating and the driver of the car responding to that . During this period the car will not start decelerating . It will keep on moving with uniform velocity of u .
Let this time lag be t .
b )
For answer see the attached file
c )
The minimum trailing distance will be the distance covered by car before it starts decelerating in response to truck's deceleration .
minimum trailing distance d = u x t
d ) u = 80 km / h = 22.22 m /s
reflex action time t = 0.1 s ( assumed time )
d = 22.22 x .1
= 2.2 m
[BWS.02]If the same experiment is repeated in different parts of the world by different scientists,
the results will be the same
the results will become invalid
the outcome of the experiment will be non testable
the outcome of the experiment will be non observable
Answer:
the results will be the same.it may be
If the same experiment is repeated in different parts of the world by different scientists, the results will be the same.
What is scientific experiment?An experiment is a procedure that is carried out to support or refute a hypothesis, or to determine the efficacy or likelihood of something that has never been tried before. Experiments shed light on cause-and-effect relationships by demonstrating what happens when a specific factor is changed.
Controls are typically included in experiments to minimise the effects of variables other than the single independent variable. This improves the reliability of the results, often by comparing control measurements to the other measurements. Scientific controls are an essential component of the scientific method.
Hence, If the same experiment is repeated in different parts of the world by different scientists, the results will be the same.
Learn more about experiment here:
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How does altitude from the surface of earth affect the time period of a simple pendulum
Answer:
because the strength of Earth's gravitational field is not uniform everywhere, a given pendulum swings faster, and thus has a shorter period, at low altitudes and at Earth's poles than it does at high altitudes and at the Equator.
A 1 m3tank containing air at 10oC and 350 kPa is connected through a valve to another tank containing 3 kg of air at 35oC and 150 kPa. Now the valve is opened, and the entire system is allowed to reach thermal equilibrium with the surroundings, which are at 20oC. Determine the volume of the second tank and the final equilibrium pressure of air.
Answer:
- the volume of the second tank is 1.77 m³
- the final equilibrium pressure of air is 221.88 kPa ≈ 222 kPa
Explanation:
Given that;
[tex]V_{A}[/tex] = 1 m³
[tex]T_{A}[/tex] = 10°C = 283 K
[tex]P_{A}[/tex] = 350 kPa
[tex]m_{B}[/tex] = 3 kg
[tex]T_{B}[/tex] = 35°C = 308 K
[tex]P_{B}[/tex] = 150 kPa
Now, lets apply the ideal gas equation;
[tex]P_{B}[/tex] [tex]V_{B}[/tex] = [tex]m_{B}[/tex]R[tex]T_{B}[/tex]
[tex]V_{B}[/tex] = [tex]m_{B}[/tex]R[tex]T_{B}[/tex] / [tex]P_{B}[/tex]
The gas constant of air R = 0.287 kPa⋅m³/kg⋅K
we substitute
[tex]V_{B}[/tex] = ( 3 × 0.287 × 308) / 150
[tex]V_{B}[/tex] = 265.188 / 150
[tex]V_{B}[/tex] = 1.77 m³
Therefore, the volume of the second tank is 1.77 m³
Also, [tex]m_{A}[/tex] = [tex]P_{A}[/tex][tex]V_{A}[/tex] / R[tex]T_{A}[/tex] = (350 × 1)/(0.287 × 283) = 350 / 81.221
[tex]m_{A}[/tex] = 4.309 kg
Total mass, [tex]m_{f}[/tex] = [tex]m_{A}[/tex] + [tex]m_{B}[/tex] = 4.309 + 3 = 7.309 kg
Total volume [tex]V_{f}[/tex] = [tex]V_{A}[/tex] + [tex]V_{B}[/tex] = 1 + 1.77 = 2.77 m³
Now, from ideal gas equation;
[tex]P_{f}[/tex] = [tex]m_{f}[/tex]R[tex]T_{f}[/tex] / [tex]V_{f}[/tex]
given that; final temperature [tex]T_{f}[/tex] = 20°C = 293 K
we substitute
[tex]P_{f}[/tex] = ( 7.309 × 0.287 × 293) / 2.77
[tex]P_{f}[/tex] = 614.6211119 / 2.77
[tex]P_{f}[/tex] = 221.88 kPa ≈ 222 kPa
Therefore, the final equilibrium pressure of air is 221.88 kPa ≈ 222 kPa
What current is needed in the solenoid's wires?
A researcher would like to perform an experiment in a zero magnetic field, which means that the field of the earth must be canceled. Suppose the experiment is done inside a solenoid of diameter 1.0 m, length 3.8 m , with a total of 5000 turns of wire. The solenoid is oriented to produce a field that opposes and exactly cancels the 52 μT local value of the earth's field.
What current is needed in the solenoid's wires? Express your answer with the appropriate units.
It has been suggested that rotating cylinders several miles in length and several miles in diameter be placed in space and used as colonies. Inhabitants of the space colonies would live on the inside surface of the cylinder. Inertial effects would resemble gravity's influence and keep them 'plastered to the surface.' Suppose that you are an inhabitant of a space colony which is 1070 miles in length and 4.86 miles in diameter. How many revolutions per hour must the cylinder have in order for the occupants to experience a centripetal acceleration equal to the acceleration of gravity
Answer:
the required revolution per hour is 28.6849
Explanation:
Given the data in the question;
we know that the expression for the linear acceleration in terms of angular velocity is;
[tex]a_{c}[/tex] = rω²
ω² = [tex]a_{c}[/tex] / r
ω = √( [tex]a_{c}[/tex] / r )
where r is the radius of the cylinder
ω is the angular velocity
given that; the centripetal acceleration equal to the acceleration of gravity a [tex]a_{c}[/tex] = g = 9.8 m/s²
so, given that, diameter = 4.86 miles = 4.86 × 1609 = 7819.74 m
Radius r = Diameter / 2 = 7819.74 m / 2 = 3909.87 m
so we substitute
ω = √( 9.8 m/s² / 3909.87 m )
ω = √0.002506477 s²
ω = 0.0500647 ≈ 0.05 rad/s
we know that; 1 rad/s = 9.5493 revolution per minute
ω = 0.05 × 9.5493 RPM
ω = 0.478082 RPM
1 rpm = 60 rph
so
ω = 0.478082 × 60
ω = 28.6849 revolutions per hour
Therefore, the required revolution per hour is 28.6849
The required revolution per hour is 28.6849
Calculation of revolution per hour:
The expression for the linear acceleration with respect to the angular velocity is
= rω²
So,
ω² = / r
ω = √( / r )
Here r represent the radius of the cylinder
ω represent the angular velocity
Now
diameter = 4.86 miles = 4.86 × 1609 = 7819.74 m
And,
Radius r = Diameter / 2 = 7819.74 m / 2 = 3909.87 m
So,
ω = √( 9.8 m/s² / 3909.87 m )
ω = √0.002506477 s²
ω = 0.0500647 ≈ 0.05 rad/s
Now
1 rad/s = 9.5493 revolution per minute
So,
ω = 0.05 × 9.5493 RPM
ω = 0.478082 RPM
Now
1 rpm = 60 rph
so
ω = 0.478082 × 60
ω = 28.6849 revolutions per hour
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Please help I’m almost done with exam
Which phrase is the best description of what a telescope does?
O A. Causes objects to grow larger
B. Transports equipment to space
C. Converts solar energy to electricity
D. Detects electromagnethwaves
Answer:
D
Explanation:
Telescopes detect electromagnetic waves from space and it travels back to the telescope lens in order for you to see.
Answer:
D
Explanation:
Ap ex science exam lol
