Question

Which prediction will most likely describe how friction will affect her findings? The distance for Trial 3 will be greater than the distance for Trial 1 partly because the weight difference of the balls will affect friction. The distance for Trial 2 will be greater than the distance for Trial 1 because the difference in surface roughness will affect friction. The distance for Trial 4 will be greater than the distance for Trial 2 partly because the weight difference of the balls will affect friction. The distance for Trial 3 will be greater than the distance for Trial 4 because the difference in surface roughness will affect friction.

Answer 1

The complete question is :

Charlie is investigating friction. She will use the same amount of force to push two wooden balls across two level surfaces. Then she will record her results in the table below.

Which prediction will most likely describe how friction will affect her findings?

Answer:

The distance for Trial 3 will be greater than the distance for Trial 4 because the difference in surface roughness will affect friction.

Explanation:

The frictional force depends greatly on the roughness of the body surfaces. It acts opposite to the direction of motion when two body surfaces have a relative motion between them.

In the context, equal mount of force is applied to push the wooden balls. So the net force which acts on the balls are :

F' = F - f

Here, F = the force applied

         f = force of friction

And f = μ.N (N = reaction force)

Here μ is the coefficient of friction that depends on the surface roughness. The frictional force will be less when the surfaces are smooth. Thus for the trails 3 and trial 4, the distance for trail 3 would be greater than trail 4 as the surface is polished and would offer less friction.