Question

A woman pushes $7.0kg$ box across a horizontal floor, applying a horizontal force of $25$ Newtons. The only other horizontal force acting on the box is an $18$ Newton force of friction.
What is the acceleration of the box while the woman pushes?

• A. $3.6m/s^2$
• B. $2.6m/s^2$
• C. $1.0m/s^2$
• D. $49m/s^2$
• E. $175m/s^2$

Answer 1

The correct option is C $1.0m/s^2$

Let a be the acceleration of the box.

From FBD, the equation of motion of the box is $ma=F-f$

or $7a=25-18=7$ or $a=1m/s^2$

Thus, option C will be correct.