Question

A weightlifter lift a weight off the ground and bolds is up, then
A. work is done in lifting as well as holding the weight
B. No work is done in both lifting and holding the weight
C. work is done in lifting the weight but no work is required by donein holding it up
D. no work is done in lifting the weight but work is required to be done in holding it up

Answer 1

Correct Answer - C
When a weight lifter lifts a weight by beight h(say).then work done by the lifting force F :
`W_(1) = Fs cos 0^(@) = + Fs`
but work done in holding it up is zero because the displacement is zero