Question

Suppose an object is accelerated by a force of 100 N. Suddenly, a second force of 100 N in the opposite direction is exerted on the object so that the forces cancel. The object

(a) is brought to rest rapidly.

(b) decelerates gradually to rest.

(c) continues at the velocity it had before the second force was applied.

(d) is brought to rest, and then it accelerates in the direction of the second force.

Short answer

The correct option is (c).

Step-by-step solution

Step 1. Forces on the object

The initial force on the object is 100 N.

The final force on the object is zero.

Assumption:

You can assume that there is not any friction.

Step 2. Concept of Newton's first law

Initially, the ball accelerates in the first 100 N force direction, and so the velocity increases.

Finally, the force on the object is zero. Therefore, after applying the second force, the acceleration of the object is zero.

Then, from Newton's first law, you get that the object is moving at a constant velocity in the direction of the first 100 N force.

Hence, the object continues at the velocity it had before the second force was applied.