A rigid body moves a distance of 10m along a straight line under the action of a force 5N. If the work done by this force on the body is 25 joules, the angle which the force makes with the force makes with the direction of motion of the body is:

Options

A. `60^(@)`.
B. `30^(@)`.
C. `45^(@)`.
D. `120^(@)`.

Answer

A

Explanation

Work is measured by the product of the applied force and the displacement of the body in the direction of the force. `:. "Work" = "Applied force xx Displacement"`
`W=(F cos theta)xx s=Fscos theta`
Given, W=25 J,F=5 N,s=10m
`:. " "cos theta=(W)/(F.s)=(25)/(5xx10)=(1)/(2)`
`implies " "theta =cos^(-1)((1)/(2))=60^(@)`
Hence, angle between force and direction of motion of the body is `60^(@)`.