Chapter 6, Problem 32A

Terry says that if an object has no acceleration, then no forces are exerted on it. Sherry doesn’t agree, but can’t provide an explanation. They both look to you. What do you say?

To determine

To identify: Whether person T or person S is correct.

Answer to Problem 32A

Person T would be correct if net force term will be used in place of forces.

Explanation of Solution

Given:

Person T says, that if the acceleration is 0, then no forces are exerted on the system. While person S disagrees with person T.

Formula used:

According to Newton’s second law:

  $a=\frac{F}{m}$

If an object has no acceleration, this means that the object is at rest or moving with a constant velocity. Then there might be several forces acting on the object.

Take an example of a toy resting on a table, then the normal force is acting on the toy and gravity is pulling down the toy. But, here net force is considered. So, the net force acting is zero. That concludes that the acceleration is directly proportional to the net force.Thus, if acceleration is zero, then there will be no net force acting on it. Person T is almost correct.

Conclusion:

Therefore, person T is correct if net force term is used.