Question

5. A 5 kg object is pushed along a rough surface. The applied force is 75 N and the friction forceis 10 N. What is the net force acting on the object? What is the acceleration caused by the netforce?

Answer 1

We have to use Newton's Second Law, knowing that the friction force is

$F_{\mu}=-mg\mu$

Then,

$F-mg\mu=ma$

Because the friction force is against the movement.

We know that m = 5kg, F = 75N, friction = 10.

$75-10=5\cdot a$

Let's solve for a

$\begin{gathered} \frac{65}{5}=a \\ a=13m/s^2 \end{gathered}$

The acceleration is 13 meters per square second.

Also, the force acting on the object is 65N because we have a net force present there.