Question

which describes a positive or negative net force acting on an object? choose four correct answers. it can cause an object at rest to remain at rest. it can cause an object to change directions. it can cause an object to start moving. it can cause an object to stop moving. it can cause an object to accelerate.

Explanation:

1. Recall Newton's laws: A net force (non - zero, positive or negative) causes a change in motion (acceleration, by \(F = ma\)).

• "It can cause an object at rest to remain at rest" is incorrect because a net force would make a resting object move (or a moving object change motion).
• "It can cause an object to change directions": A net force can change the velocity vector (direction is part of velocity), so this is correct.
• "It can cause an object to start moving": A net force on a stationary object (net force ≠ 0) will make it start moving, correct.
• "It can cause an object to stop moving": A net force opposite to the motion can stop it, correct.
• "It can cause an object to accelerate": By \(F = ma\), net force causes acceleration, correct.

Answer:

• It can cause an object to change directions.
• It can cause an object to start moving.
• It can cause an object to stop moving.
• It can cause an object to accelerate.