Question

a force of 20 Newton being applied on a body if the angle between the line of action and the displacement is 45 degree and the amount of displacement is 4m then find out the work done

Answer 1

work = fscos45°
$= 20 \times 4 \times \cos(45)$
$= 40 \sqrt{2} \: joule$

Answer 2

Here we are given that force applied is 20 N. since the line along which force acts is not parallel to horizontal rather it is inclined to it at angle of 45 degrees. In this scenario the formula to calculate work done is :

$fs\cos( \alpha )$
where 'f' is Force, 's' is Displacement and 'cos alpha' is cos of angle at which force acts to the horizontal.
Now, coming to the Question we have:
F=20N
S=4m
cos alpha=cos(45) = 1/1.414 = 0.7

Put above values in the formula and we get:
W= 20×4×0.7
W = 56 joules.