Question

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?

a. 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.

b.The distance for Trial 2 will be greater than the distance for Trial 1 because the difference in surface roughness will affect friction.

c.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.

d.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

D the distance for trial 3 will be greater than trial 4

Answer 2

Answer: d.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 force of friction depends upon the roughness of the surface. Force of friction acts in the opposite direction of motion when the two surface tend to have relative motion. In the given situation, equal amount of force is applied to push the wooden balls.

Net force acting on the balls with which they move:

F' = F -f

where f is the force of friction and F is the applied force.

f = μ N

where N is the reaction force

μ is the coefficient of friction which depends upon roughness of the two surfaces. Smoother the surface, lesser would be the frictional force. Thus, for trial 3 and 4, the distance would be greater for trial 3 as there is polished surface which would offer lesser friction.