Question

Ram carried four balls of metal through a height of 10 metres. The process involved some work done. If he carries two similar balls of metal through a height of 20 metres, work done in this case is ______ the first case. (Assume the balls are of weight $1N$ each.)

• A. more than
• B. less than
• C. equal to
• D. double

Answer 1

The correct option is C equal to

Work done is the product of force and displacement.
(work done =force x displacement).
The force required to lift one ball = weight of each ball = 1 Newton.
To lift 4 balls 4 Newton is required.
hence the work done to lift 4 ball in first case will be -
work done$=4\times 10=40J.$
Similarly for the second case,
work done (second case)$=2\times 20=40J.$
Hence the work done will be equal for both cases.