Physics, 10.03.2020 07:28 Edithh

A box of bananas weighing 40.0 NN rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0.40 and the coefficient of kinetic friction is 0.20.
(a) If no horizontal force is applied to the box and the box is at rest, how large is the friction force exerted on the box?
(b) What is the magnitude of the friction force if a monkey applies a horizontal force of 6.0N to the box and the box is initially at rest?
(c) What minimum horizontal force must a monkey apply to start the box in motion?

Answers: 3

Show answers

Answers

Answer from: elijah207

a) 0 N

b) 6 N

c) So the applied force must be greater than 16 newton.

Explanation:

Given:

weight of the box, $w=40\ N$

coefficient of static friction between the box and horizontal surface, $\mu_s=0.4$

coefficient of kinetic friction, $\mu_k=0.2$

Here the given value of coefficient of static friction is understated, it is given here as the maximum value of the coefficient of static friction which is variable according to the applied force on the body tending to promote a relative motion between the surfaces.

When no horizontal force is applied on the box and the box is at rest then according to the Newton's first law of motion the box tends to have its initial state of rest and all the forces acting on the box are in equilibrium. Hence no frictional force acts on the box.

When a monkey applies a force of 6 N on the box and it does not move then the contact surface friction also applies the equal amount of force in the opposite direction which balances out the applied force, this will happens upto the maximum coefficient of friction which is stated as coefficient of static friction in the question.

the minimum force required to move the box must be greater than the maximum force of friction which resists the relative motion.

We have the maximum frictional force as:

$f=\mu_s.w$

$f=0.4\times 40$

$f=16\ N$

So the applied force must be greater than 16 newton.

Answer from: Quest

1) when you rub your hands together quickly, the kinetic energy is converted to mechanical energy.2) thermal energy from the sun travels to earth as infrared waves.3) energy is transferred through the matter of space by electromagnetic waves. 4) when a match is burned, chemical potential energy is converted to thermal and radiant energy. 5) seismicwaves are caused by back and forth movement , or vibration, of an object. 6) mechanicalenergy in an engine changes thermal energy into kinetic energy to make a car move.

Answer from: Quest

B) as the temperature increases, the kinetic energy of the particles increases.|-/

Another question on Physics

Physics, 21.06.2019 16:10

At what point the certain object feels zero garvitational force between earth and the moon. take the required information from the book.required: distance away from earth or moon

Answers: 1

Answer

Physics, 22.06.2019 00:30

What are the theoretical properties of a gas at a temperature of 0 kelvin?

Answers: 3

Answer

Physics, 22.06.2019 06:20

Part 1: a magnetic levitation or maglev train rides rails without touching them. explain how this works using your data. include the appropriate magnet drawing in your answer. part 2: two objects are near a bar magnet. one is about 1 cm away, while the other is 6 cm away. compare and contrast the magnetic force that affects each object. use your data to answer the question

Answers: 1

Answer

Physics, 22.06.2019 11:30

This punnett square shows the cross between two pants. one parent has round seeds (rr). and the other parent has wrinkled seeds (rr) which best describes their offspring as shown in this cross?

Answers: 1

Answer

You know the right answer?

A box of bananas weighing 40.0 NN rests on a horizontal surface. The coefficient of static friction...

Questions