Question

Friction is a force that usually slows down or prevents motion. However, friction can sometimes cause an object to speed up, such as when you walk forward. The frictional force between the ground and your foot is what actually pushes you forward (as your foot pushes backward on the ground). Identify which instance below describes a scenario in which the frictional force causes the object it acts upon to speed up rather than slow down.

A package on a moving conveyer belt
A sled on snow
Sliding a book across your desk
Air resistance on a moving car

Answer 1

Step-by-step explanation:

The scenario in which frictional force causes the object it acts upon to speed up rather than slow down is "A package on a moving conveyor belt."

When a package is placed on a moving conveyor belt, the frictional force between the bottom of the package and the belt opposes the relative motion between the two surfaces. However, in this case, the direction of the applied force (from the moving belt) is in the same direction as the motion of the package. As a result, the frictional force helps propel the package forward, allowing it to speed up.

In the other scenarios mentioned:

- A sled on snow experiences friction opposing its motion, which slows it down.

- Sliding a book across your desk experiences friction that opposes the sliding motion, causing the book to slow down.

- Air resistance on a moving car acts opposite to its motion, slowing it down.