Question

a young man exerted a force of 900 newtons for 10 seconds to push his car that had ran out of gas. however he could not get the car to move. how much work did he do?
A-9000 joules
B-9000 watts
C-90 joules
D-90 watts
E-no work was done

Answer 1

Work done is defined as product of force and displacement of point of application of force.

So here we will have

$W = F.d$

now since here after applying the force the car is not displaced from its position

So here we have

d = 0

so work done is given as

$W = 900 \times 0 = 0$

so there is no work done in this case