Question

A boy pull a wagon with a Force of 45N by means of a rope that makes an angle of 40 degree with the ground.how much work does he do in moving the wagon.

Answer 1

Mechanical work

$$W=F\cdot S\cdot cos(\alpha)$$

We can define work per length

$$\frac{W}{S}=F\cdot cos(\alpha)$$

Calculating

$$\frac{W}{S}=45\cdot cos(40)=34.5 (\frac{J}{m})$$