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

To determine whether each statement describes a positive or negative net force acting on an object, let's analyze them one by one:

1. It can cause an object to accelerate. - Positive Net Force: A net force acting on an object results in acceleration according to Newton's second law of motion (F = ma).

2. It can cause an object to stop moving. - Negative Net Force: A net force opposing an object's motion can decelerate (or stop) it, effectively acting as a negative net force.

3. It can cause an object to start moving. - Positive Net Force: A net force can initiate motion in an object that is at rest.

4. It can cause an object to change directions. - Positive Net Force: A net force can change the direction of an object's velocity, which is also a form of acceleration.

5. It can cause an object at rest to remain at rest. - No Net Force: This statement describes a situation where there is no net force acting on the object, as an object at rest will stay at rest unless acted upon by an unbalanced force.

In summary:

• Positive net force: 1, 3, 4
• Negative net force: 2
• No net force: 5