Question

A boy pulls a wagon with a force of 7 Newtons east as another boy pushes it with a force of 4 Newtons east, the sliding frictional force is 3 Newtons. What is the net force? If the wagon is accelerating at a rate of 2 m/s2, what is the mass of the wagon?

Answer 1

Given,

The force with which the wagon is being pulled, F₁=7 N

The force with which the wagon is being pushed, F₂=4 N

The frictional force, f=3 N

The acceleration of the wagon, a=2 m/s²

The frictional force is a force that opposes the motion of an object. Thus the frictional force is in the opposite direction of the applied forces.

The net force on the wagon is given by,

`\begin{gathered} F_n=F_1+F_2-f \\ =7+4-3 \\ =8\text{ N} \end{gathered}`

Thus the net force on the wagon is 8 N.

From Newton's second law, the net force on the wagon is given by,

`F_n=ma`

Where m is the mass of the wagon.

On substituting the known values,

`\begin{gathered} 8=m*2 \\ \Rightarrow m=(8)/(2) \\ =4\text{ kg} \end{gathered}`

Thus the mass of the wagon is 4 kg.