Question

Fill in the blank question.

A force of 40.0 N accelerates a 5.0-kg block at 6.0 m/s2 along a horizontal surface.

a. What would be the block's acceleration be if the surface were frictionless?
m/s2

b. How large is the kinetic friction force?
N

c. What is the coefficient of kinetic friction?

Answer 1

a. The block's acceleration would be 6.0 m/s2 if the surface were frictionless.

b. The kinetic friction force can be calculated using the formula: f_k = friction_coefficient * f_norm.

where f_norm is the normal force.

The normal force is equal to the weight of the object, which is given by the formula: f_norm = m*g

where m is the mass of the object and g is the acceleration due to gravity.

So f_norm = 5.0 kg * 9.8 m/s^2 = 49 N

And the kinetic friction force is: f_k = friction_coefficient * f_norm = friction_coefficient * 49 N

c. The coefficient of kinetic friction can be found by dividing the kinetic friction force by the normal force:

friction_coefficient = f_k / f_norm

It is important to notice that these formulas are based on the assumption that the surface is frictionless. If the surface isn't frictionless, it would be necessary to measure the force of friction and the normal force to calculate the coefficient of kinetic friction.