Question

Which describes a positive or negative net force acting on an object? Check all that apply.

It can cause an object to accelerate.
It can cause an object to stop moving.
It can cause an object to start moving.
It can cause an object to change directions.
It can cause an object at rest to remain at rest.

Answer 1

Check the first four; not the last.

- It can cause an object to accelerate. — Yes. (Nonzero net force produces acceleration, F = ma.)
- It can cause an object to stop moving. — Yes. (A net force opposite the motion slows and can stop the object.)
- It can cause an object to start moving. — Yes. (A net force on a resting object produces acceleration from rest.)
- It can cause an object to change directions. — Yes. (A net force perpendicular to velocity changes direction.)
- It can cause an object at rest to remain at rest. — No. (Remaining at rest requires zero net force.)