Question

Jason is pulling a box across the room. He is pulling with a force of 16 newtons and his arm is making a 71 angle with the horizontal, if the box weighs 15 newtons what is the netforce on the box in the vertical direction? Treat up as the positive direction, and down as the negative direction

Answer 1

We know that

• The force is 16 Newtons.

,

• The angle of application is 71 degrees.

,

• The box weighs 15 Newtons.

First, let's make a free-body diagram.

As you can observe, the vertical vectors are the weight of the box and the vertical component of the applied force.

`\Sigma F_y=F_y-W`

Where each force is defined as follows

`\begin{gathered} F_y=F\cdot\sin \theta \\ W=mg \end{gathered}`

Let's use the expressions above to find the net vertical force.

`\begin{gathered} \Sigma F_y=F\cdot\sin \theta-mg=16N\cdot\sin 71-15 \\ \Sigma F_y\approx0.13N \end{gathered}`

Therefore, the net vertical force is 0.13 Newtons.