Answer:
Because the mechanical advantage of the machine is affected by friction and weight but velocity ratio is not. So, mechanical advantage is less than velocity rate. Thus, the machine's efficiency is less than 100% and can't be a perfect machine
The correct answer is A. 250N
Work is a product of force and distance.
That is, work done=force×distance
Therefore substituting for the values in the question:
500J=force×2m
force= 500Nm/2m=250N
another unit for work done is Nm as force as the SI unit of force is newtons and distance in meters
