The coefficient of kinetic friction between the box and the floor is 0.323.
By Newton's Law of Motion we understand that an object is at equilibrium if and only if it is at rest or it is moving at constant velocity. If a horizontal force is applied on the box and it is moving, then a force with equal magnitude and opposed to that force must exists, which corresponds to the kinetic friction. Let suppose that the box is moving on a horizontal ground.
The equation of equilibrium for the box is described below:
[tex]\Sigma F = P - \mu_{k}\cdot m\cdot g = 0[/tex] (1)
Where:
[tex]P[/tex] - External force, in newtons.[tex]\mu_{k}[/tex] - Kinetic coefficient of friction, no unit.[tex]m[/tex] - Mass, in kilograms.[tex]g[/tex] - Gravitational constant, in meters per square second.An expression for the kinetic coefficient of friction is derived by clearing the variable in (1):
[tex]\mu_{k} = \frac{P}{m\cdot g}[/tex] (2)
If we know that [tex]P = 38\,N[/tex], [tex]m = 12\,kg[/tex] and [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], then the kinetic coefficient of friction is:
[tex]\mu_{k} = \frac{38\,N}{(12\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)}[/tex]
[tex]\mu_{k} = 0.323[/tex]
The coefficient of kinetic friction between the box and the floor is 0.323.
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A car's acceleration is 3m/s2. If the car started at rest and it only took 10s for the car to reach this acceleration, what is the car's final velocity?
Answer:
30m/s
Explanation:
From law of motion equation
Vf= Vi + at
Where Vf= final velocity
Vi= initial velocity=0(the car started at rest)
a= acceleration= 3m/s2
t= time= 10s
Then substitute into the equation to get the final velocity.
Vf= 0+(10×3)
Vf= 30m/s
Hence, the car's final velocity is 30m/s
What is the force required to move a 5,000 kg car with an acceleration of 4 m/s?
Answer:
20000
Explanation:
f=m*a
mass=5000
a=4
5000*4=20000
with what force will the a car hit a tree if the car has a mass of 3,000 kg and a acceleration of 2m/s^2
Answer:
The answer is 6000 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3000 × 2
We have the final answer as
6000 NHope this helps you
Line BD is the perpendicular bisector of CA. What additional information would be sufficient to prove that triangle BDA is congruent to triangle BDC by SAS.
Answer:
DA ≅ DC (since BD is equidistant to A and C)
Explanation:
A line bisector is one that divides a given line into two equal parts. And which is equidistant from the ends of the bisected line.
Given: BD is the perpendicular bisector of CA.
Thus:
BD is equidistant to A and C
Also, BD is a common side to ΔBDA and ΔBDC
DA ≅ DC (since BD is equidistant to A and C)
<BDA ≅ <BDC (congruent property)
<ADB ≅ <DBC (alternate angle property)
<CDB ≅ <ABD (alternate angle property)
Thus,
ΔBDA ≅ ΔBDC (Side-Angle-Side, SAS, congruent property)
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the graph represents the motion of a car moving along a staright highway describe in words the motion car
The red car drive on a motor way in 800 m/s.The
driver of the Green car want to dive in that speed in
20 seconds.How many distance can he travel?
As the ball rolls down the ramp, there are changes in kinetic and potential energy. How much kinetic energy does the
ball have when it reaches point B?
A) 0J
B) 25J
C) 50J
D)100J
The answer is C, 50J
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Which experimental discovery led Niels Bohr to revise Rutherford's model of
the atom?
A. Most alpha particles pass straight through a thin sheet of gold
foil.
B. Electrons have more energy the farther they are from the nucleus.
C. A few alpha particles bounce off a thin sheet of gold foil.
D. The beam in a cathode ray tube is moved by an electric force.
Answer:
Electrons have more energy the farther they are from the nucleus.
Explanation:
A P E X
Which is the best description of a balanced diet?[food pyramid]
A. A vegetarian diet that includes no meat
B. A diet that consists of fewer than 2,000 calories per day
C. A diet that includes a wide variety of nutritious foods
D. A diet in which you eat at most three times a day
Answer:
A vegetarian diet that includes no meet is the best description of a balanced diet
Answer:
I should be B
Explanation:
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A projectile has an initial x-velocity of 4 m/s, and an initial y-velocity of 27.7 m/s. What is the range of the projectile
Answer:
I love yourself help yourself
Cellular respiration takes place in the mitochondria of cells.
Answer:
True
Because mitochondria is the powerhouse of the cell.
Explanation:
Hope this helps you
Answer:
True
Explanation:
The human body is a system of systems that rely on each other to sustain a life. Explain how.
Which two elements have similar properties and 8 electrons in their
outermost shells?
Answer:
A. Neon and argon
General Formulas and Concepts:
Reading the Periodic Table of ElementsValence Shell configurationsExplanation:
Elements that have a full valence shell (the outermost shell), are in Group 18 of the Periodic Table.
Because their outermost shell is full, they are inert, meaning that they do not like to bond or react with other elements.
Therefore, these gases with a stable full valence shell are known as Noble Gases.
HeliumNeonArgonKryptonXenonRadonA. would be the correct answer.
Answer:argon and krypton
Explanation:
Noble gases
What moon phase would happen immediately before the shown phase?
Waning Crescent
Waxing Gibbous
Full Moon
New Moon
Answer:
waning crescent
Explanation:
Waxing Crescent - Rises before noon, transits meridian before sunset, sets before midnight
Answer:
new moon
Explanation:
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While john is traveling along a straight in interstate highway, he notices that the mile marker reads 242 mm. John travels until he reaches the 147 km marker and then retraces his path to the 161km marker. What is John's resultant displacement from the 242km marker? How far has he traveled answer in units of km
Complete Question
While john is traveling along a straight in interstate highway, he notices that the mile marker reads 242 km. John travels until he reaches the 147 km marker and then retraces his path to the 161 km marker. What is John's resultant displacement from the 242 km marker? How far has he traveled answer in units of km
Answer:
The resultant displacement [tex]\Delta x _{1 , 3} = 81 \ km[/tex]
The total distance traveled by john is [tex]x_t =109 \ km[/tex]
Explanation:
From the question we are told that
The first position of john from the finish point is [tex]x_1 = 242 \ km[/tex]
The second position of john from the finish point is [tex]x_2 = 147 \ km[/tex]
The third position of john from the finish point is [tex]x_3 = 161 \ km[/tex]
Generally the displacement from the 242 km marker is mathematically represented as
[tex]\Delta x _{1 , 3} = x_1 - x_3[/tex]
Here we used [tex]x_3[/tex] instead of [tex]x_2[/tex] because [tex]x_3[/tex] is further than [tex]x_2[/tex] from the finish point
=> [tex]\Delta x _{1 , 3} = 81 \ km[/tex]
Generally the total distance traveled by John is mathematically evaluated as
[tex]x_t = [x_1 - x_2 ] + [x_3 - x_2][/tex]
=> [tex]x_t = [242 - 147 ] + [161 - 147][/tex]
=> [tex]x_t =109 \ km[/tex]
15 points. give me the method.
4.The difference of wavelength of two waves of frequencies 640Hz and 480Hz respectively in a certain medium is 1m. Find the velocity of sound in that medium.
Answer:
[tex] \boxed{{160 \: m(s)}^{ - 1} }[/tex]
Explanation:
[tex]if \:the \: frequencies \: are \to \\ f_{1} = 640Hz \\ and \\f_{2} = 480Hz \: \\ but \: \boxed{v = f \gamma }: f = \frac{v}{ \gamma } \\ if \: \gamma_{1} - \gamma _{2} = 1 = \gamma \\ f_{1} - f_{2} = 640 - 480 = \boxed{ 160Hz} = f \\ v = f \gamma = 160 \times 1 = \boxed{{160 \: m(s)}^{ - 1} }[/tex]
- A type of elevator called a cage is used to raise and lower miners in a mine
shaft. Suppose the cage carries a group of miners down the shaft. If the
unbalanced force on the cage is 60.0 N, and the mass of the loaded cage is
1.50 10 kg, what is the acceleration of the cage?
What is the Law of Conservation of Energy?
Answer:
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
Explanation:
Hope this helped, Have a Great Day!!
A bicycle travels 22 km in 0.50 hr. What is its average speed?
Answer:
22/0.50=44
Explanation:
average speed= distance / time
Please need help ASAP 15 points????I need a,b,c
Answer:
The acceleration is negative and very close to zero.
Very Small, because it slowly comes to a stop, which means there is nothing to stop it any faster
It would keep traveling in that direction without slowing down
Explanation:
Answer:
A,B,C
Explanation:
A) because the ball is slowing down that means that the acceleration is changing and is slowing. It also means that it has negative acceleration because it is going the opposite way of velocity. When it stops then there is no more acceleration
B) Net force is calculated by the sum of the forces that are acting on the object. If the net force is unbalanced then it will speed up, slow down, or change direction. So basically, net force is an unopposed force that causes a change in motion. First, it has a net force because it's moving and is not in equilibrium. Second, the net force would be changing as it is stopping. When it stops then it would be in static equilibrium. Basically, the net force is changing as the speed slows down until it comes to a state of equilibrium.
C) If it was in space then it would never stop. Because of the law of inertia, an object in motion will stay in motion as long as there are no other opposing forces. Because there really aren't opposing forces in space, it would keep on going forever.
After our sun leaves the main sequence it will most likely
A.) become a supergiant and explode in a supernova explosion
B.) become a giant and eventually form a black hole
C.) become a supergiant and eventually form a dwarf star
D.) become a giant and eventually form a dwarf star
A rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a
centripetal acceleration of 4.0 m/s2. If the length of the rope is 3.1 m, what is the girl's
tangential speed?
The amount of work done to bring an electron (q = −e) from right side of hydrogen nucleus to left side in the k shell is__________. Let the radius (r) of atom is 52 pm a) Zero b) infinity c) Fr d) 2Fr
Answer:
d) 2Fr
Explanation:
We know that the work done in moving the charge from the right side to the left side in the k shell is W = ∫Fdr from r = +r to -r. F = force of attraction between nucleus and electron on k shell. F = qq'/4πε₀r² where q =charge on electron in k shell -e and q' = charge on nucleus = +e. So, F = -e × +e/4πε₀r² = -e²/4πε₀r².
We now evaluate the integral from r = +r to -r
W = ∫Fdr
= ∫(-e²/4πε₀r²)dr
= -∫e²dr/4πε₀r²
= -e²/4πε₀∫dr/r²
= -e²/4πε₀ × -[1/r] from r = +r to -r
W = e²/4πε₀[1/-r - 1/+r] = e²/4πε₀[-2/r} = -2e²/4πε₀r.
Since F = -e²/4πε₀r², Fr = = -e²/4πε₀r² × r = = -e²/4πε₀r and 2Fr = -2e²/4πε₀r.
So W = -2e²/4πε₀r = 2Fr.
So, the amount of work done to bring an electron (q = −e) from right side of hydrogen nucleus to left side in the k shell is W = 2Fr
Is it possible to generate emf without rotating the coil explain
Answer:
It's not possible.
Explanation:
It's not possible.
This is because when a coil is rotated in a magnetic field about a line which is not the axis of the coil, the magnetic coil with a link going through the coil will change and thus an EMF will be produced.
Now, this EMF produced is gotten as a result of cutting action through lines of magnetic flux gotten through rotation (physical movement) of the coil through space.
Faraday's law allows finding the result for whether it is possible to create induced electromotive force (emf) without rotating the coil are:
Producing a pulsating voltage is possible change the magnetic field the area of the loop. Producing constant voltage is not possible since a uniform change of some parameter is required and the only one that can change is the angle constantly.
Faraday's Law states that by varying the magnetic flux an electromotive force is produced.
[tex]emf = - \frac{d \Phi_B }{dt} \\\Phi_B = B . A[/tex]
Where emf is the induced voltage, Ф the magnetic flux, B the magnetic field and A the area of the loop
We can write the flow explicitly.
Ф = B A cos θ.
Therefore we see that there is some form of having this changing flow:
Changing the magnitude of the magnetic field. Changing the area of the loop. Changing the angle between the normal to the area and the magnetic field direction.
The first two methods are used in pulsating fields, that is, a voltage is obtained for a short period of time.
The last method is used in equipment that can give indicated voltage in a constant way, it is the method used to produce electricity, it consists of an external system that rotates the loop with a constant speed and produces an output voltage.
In conclusion using Faraday's law we can find the result for whether it is possible to create induced electromotive force (emf) without rotating the coil are:
Producing a pulsating voltage is possible change the magnetic field the area of the loop Producing constant voltage is not possible since a uniform change of some parameter is required and the only one that can change is the angle constantly.
Learn more here: brainly.com/question/1640558
the value of g is greater at the poles than at the equator why
Answer:
because the gravitational pull is maximum at the poles and decreases as it comes down toward the equator.
A paintball is fired horizontally from a tower 45 m above the ground. If the paintball gun fires at 90 m/s… How long does it take for the paintball to hit the ground? How far away from the tower will the paintball land?
Answer:
The time taken for the paint ball to hit the ground is [tex]t = 2.143 \ s[/tex]
The distance of the landing point from the tower is [tex]d = 192.86 \ m[/tex]
Explanation:
From the question we are told that
The height of the tower is [tex]h = 45 \ m[/tex]
The speed of the paintball in the horizontal direction is [tex]v_x = 90 \ m/s[/tex]
Generally from kinematic equation we have that
[tex]h = ut + \frac{1}{2} at^2[/tex]
Here u is the initial velocity of the paintball in the vertical direction and the value is 0 m/s , this because the ball was fired horizontally
a is equivalent to [tex]g = 9.8\ m/s^2[/tex]
t is the time taken for the paintball to hit the ground
So
[tex]45 = 0* t + \frac{1}{2} 9.8 * t^2[/tex]
=> [tex]t = 2.143 \ s[/tex]
Generally the distance of its landing position from the tower is
[tex]d = v * t[/tex]
=> [tex]d = 90 * 2.143[/tex]
=> [tex]d = 192.86 \ m[/tex]
The relationship that exists between gravity and distance and mass respectively.
A. The gravitational force is directly proportional to the distance between objects and inversely
proportional to the mass of the objects.
B. The gravitational force is inversely proportional to the distance between objects and directly
proportional to the mass of the objects.
C. The gravitational force is inversely proportional to the distance between objects and inversely
proportional to the mass of the objects.
D. The gravitational force is directly proportional to the distance between objects and directly
proportional to the mass of the objects.
Answer:
D...............................
Suppose an object has a velocity of -7 m/s at t=0. What will the velocity be after 4 seconds if the acceleration of the object is +1 m/s^2?
Answer:
Vf = - 3 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} =v_{o} +a*t[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = - 7 [m/s]
a = acceleration = 1 [m/s²]
t = time = 4[s]
Now replacing:
Vf = -7 + (1*4)
Vf = - 3 [m/s]
All elements are composed of extremely small particles called
Differentiate between the focus and the epicenter of an earthquake.
