1. Derive an expression for the work done when a force is acting on an object in the direction of its displacement.
  2. A pair of bullocks exerts a force of 150 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?

Asked by Topperlearning User | 20th Sep, 2016, 10:02: AM

Expert Answer:

  1. When a force F displaces a body through a distance s in the direction of the applied force, then the work done W on the body is given by the expression:
    Work done = Force × Displacement

    W = F × s  
     
  2. Work done by the bullocks is given by the expression:
    Work done = Force × Displacement
    W = F ×  s
    Where,

    Applied force, F = 150 N
    Displacement, s = 15 m
    W = 150  × 15 = 2250 J   
    Hence, 2250 J of work is done in ploughing the length of the field.

Answered by  | 20th Sep, 2016, 12:02: PM