Under the influence of a force, an object of mass 4 kg
accelerates from 3 m/s to 6 m/s in 8 s. How much work
was done on the object during this time?

53.3J

Explanation:

Given parameters:

Mass of object  = 4kg

Initial velocity  = 3m/s

Final velocity  = 6m/s

time taken  = 8s

Unknown:

Amount of work done on body = ?

Solution:

Work done is the force applied to move a body through a particular distance.

                     Work done  = force x distance

let us find force and distance:

Using newton's second law of motion:

         F = ma

where m is the mass and a is the acceleration

First find the acceleration;

 Acceleration  =

          V is the initial velocity

           U is the final velocity

   Input the parameters;

      a  =  = 0.38m/s²

     F  = 4 x 0.38  = 1.5N

To find the distance;

  V²  = U²  + 2as

 where s is the distance

         6²  = 3²  + 2(0.38)s

      s  = 35.5m

Work done   = 1.5 x 35.5  = 53.3J