Question

How much work is done by the boy pulling his sister 36 m in a wagon as shown in the figure below? Assume no friction acts on the wagon. (Assume d = 36 m and F = 52 N.)

Answer 1

The amount of work done is `"1600 N"*"m"`at an angle of `30^("o")`, and a horizontal displacement of `"36 m"`.

Explanation:

Work is done when a force acts on a body, causing that body to move a given number of meters in the same direction as the force. The formula for work is:

`W=F*d*costheta"`, where `W` is work in Newton-meters, `("N"*"m")`, force is Newtons, `("N")`, and `("d")` is the displacement in meters over which the force is applied, and `theta` is the angle over which the force is applied.

Known:
`"F=52 N"`
`"d=36 m"`
`theta=30^("o"`

Unknown: `W`

`W=52"N"xx36"m"xx"cos30"^("o")=1600"N"*"m"` (rounded to two significant figures)

The amount of work done is `"1600 N"*"m"`at an angle of `30^("o")`, and a horizontal displacement of `"36 m"`.