Question

Computing Work Find the work done by a force of $5$pounds acting in the direction $60°$to the horizontal in moving an object $20$feet from $(0,0)$ to $(20,0)$.

Short answer

The work done is $50ft-lb$.

Step-by-step solution

Step 1. Given information 

We are given that work done by a force of $5$pounds acting in the direction $60°$to the horizontal.

Step 2. Finding the work done

It can be seen that the force is at ${60}^{\circ }$from the horizontal which causes a horizontal displacement of $20$ feet. So, the component of the force in the direction of the displacement is,

$F\cos 60°=\frac{F}{2}$

We know that,

$$\begin{gathered} W=\text{Force}\times \text{displacement} \\ W=\frac{F}{2}\times r \end{gathered}$$

Putting the value of r, we get

localid="1647312942535" $$\begin{gathered} W=\frac{5lb}{2}\times 20ft \\ W=50ft-lb \end{gathered}$$