Question

a vehicle of known mass accelerates along a straight path. what caused this acceleration, according to newtons second law of motion? ○ an unbalanced force has acted on the vehicle. ○ a balanced force has acted on the vehicle. ○ the mass of the vehicle has changed. ○ the direction of the vehicle has changed.

Explanation:

Newton's second law of motion states that the acceleration of an object is directly proportional to the net (unbalanced) force acting on it and inversely proportional to its mass ($F = ma$). A balanced force means the net force is zero, so there would be no acceleration. Changing mass or direction (while moving straight here) isn't the cause of acceleration as per the law; the key is an unbalanced force.

Answer:

An unbalanced force has acted on the vehicle.