Q16DQ - University Physics with Modern Physics

Question

Students sometimes say that the force of gravity on an object is 9.8 $\mathbf{m}\mathbf{/}{\mathbf{s}}^{\mathbf{2}}$. What is wrong with this view?

Step-by-Step Solution

Answer

The g that is 9.8 m/s² is not a force; it is the acceleration due to gravitational force.

Step 1: Define Newton’s Second law

A body accelerates when a net force acts on it and travels in the same direction as the net force. The product of mass and acceleration vector is equal to the force vector.

$\sum \overrightarrow{F}=m\overrightarrow{a}$

Step 2: Comment on the given view.

Force being mass times acceleration is just an empirical equation that is used to calculate net force. Even though mass times acceleration equals the net force, ma or just acceleration is not a force. Acceleration is an effect of a non-zero net force; it itself is not a force. The g that is 9.8 m/s² is an acceleration due to gravitational force.