An object rests on a horizontal frictionless surface. A horizontal force of magnitude F is applied. This force produces an acceleration:
A) only if F is larger than the weight of the object
B) only while the object suddenly changes from rest to motion
C) always
D) only if the inertia of the object decreases
E) only if F is increasing

Question

Quizplus · Accepted Answer

According to Newton's second law, the acceleration of an object is directly proportional to the net force applied to the object, and inversely proportional to its mass. In this case, the surface is frictionless, so there is no other force acting in the horizontal direction to oppose the applied force. Therefore, the acceleration produced by the force is always present, and is given by a = F/m, where F is the applied force and m is the mass of the object.

An Object Rests on a Horizontal Frictionless Surface