Question

A 2 kg mass kept on a horizontal table is acted upon by a force of 5 N at an angle of 60° from horizontal and moved through a distance of 3 m on the table. The work done on the body is 

(1) 5 J 

(2) 7.5 J 

(3) 10 J 

(4) 15 J

Answer 1

Correct option is (2) 7.5 J 

Given

Mass = 2 kg

Force = 5 N

Distance = 3 m

The angle between force and distance traveled is 

\(\theta = 60 ^\circ\)

Work done on the body

⇒ W = F x S x Cos θ

⇒ W = 5 x 3 x Cos \(60 ^\circ\)

⇒ W = 15 x \(\frac {1}{2}\)

⇒ W = 7.5 J

Thus, we conclude that the work done on the body is W = 7.5 J.