Question

Friction is a force that opposes motion. Manuel and his lab partner set up the incline you see here. One wooden board was left bare, and the other was covered with carpet. The boys used a spring scale to pull blocks, of equal mass, up the incline. A force of 2.5N was used to pull the block up the bare wood side; a force of 7.5N was used to pull the block up the carpeted side. Their data supported their hypothesis. Manuel and Kai set up another experiment to determine how different shapes impact the amount of friction needed to pull objects up the bare wooden board. Predict in which trial would the friction force between the object and the wooden board be the LOWEST?

a. Trial 1
b. Trial 2
c. Trial 3
d. Trial 4

Answer 1

The friction force between the object and the wooden board would be the lowest in Trial 4 because different shapes can reduce the contact area between the object and the wooden board.

Step-by-step explanation:

The friction force between the object and the wooden board would be the lowest in Trial 4.

Friction depends on the materials involved and is proportional to the normal force pushing the objects together. In Trial 4, the amount of friction is reduced because different shapes are used, which can reduce the contact area between the object and the wooden board. With less contact area, the friction force is lower.