If a runner is accelerating along a flat race track, which statement is true?

Question

(1 point)
The gravitational force of the runner on the ground is greater than the normal force of the ground
on the runner.
The running force provided by the runner is greater than the drag on the runner from the air.
The drag on the runner from the air is greater than the running force provided by the runner.
The normal force of the ground on the runner is greater than the gravitational force of the runner
on the ground.

Answer 1

In the context of a runner accelerating along a flat race track, let's analyze each statement:

1. The gravitational force of the runner on the ground is greater than the normal force of the ground on the runner.

   • This statement is false. In a static situation or uniform motion, the gravitational force acting on the runner is balanced by the normal force from the ground.

2. The running force provided by the runner is greater than the drag on the runner from the air.

   • This statement can be true if the runner is accelerating. For the runner to accelerate, the forward running force must exceed the backward drag force.

3. The drag on the runner from the air is greater than the running force provided by the runner.

   • This statement is false because if the drag were greater than the running force, the runner would not be able to accelerate.

4. The normal force of the ground on the runner is greater than the gravitational force of the runner on the ground.

   • This statement is false. Under normal conditions on a flat surface, the normal force equals the gravitational force.

Given this analysis, the correct statement is:

The running force provided by the runner is greater than the drag on the runner from the air.