Answer :
Answer:
Work done, W = -1440 J
Explanation:
It is given that,
Mas of an object, m = 60 kg
Initial velocity of the object, u = 8 m/s
Final velocity of an object, v = 4 m/s
We know that work done is equal to change in kinetic energy of an object as per work energy theorem.
[tex]W=\dfrac{1}{2}mv^2-\dfrac{1}{2}mu^2[/tex]
[tex]W=\dfrac{1}{2}m(v^2-u^2)[/tex]
Putting all the values in above equation we get :
[tex]W=\dfrac{1}{2}\times 60\ kg((4\ m/s)^2-(8\ m/s)^2)[/tex]
W = -1440 J
So, the work done by the object is -1440 Joules. Hence, the correct option is (A) " -1440 J ".
