Chapter 4, Problem 4Q

If the acceleration of an object is zero, are no forces acting on it? Explain.

To determine

Is it possible to have a force acting on an object is zero if the acceleration is zero

Answer to Problem 4Q

Solution:

There will be no forces if acceleration is zero

Explanation of Solution

According Newton’s second law

$F=ma$

where a is the acceleration, m is the mass of the object and F is the force

If acceleration is zero

$\begin{array}{l}F=m\times 0\end{array}$

$\begin{array}{l}F=0\end{array}$

If acceleration is zero then the net force applied to it will be zero from above equation. It is possible to have the net force on the object to be zero if acceleration is zero. There can be forces acting on the object as long as the vector sum of the forces is zero.