A block of mass 30.0 kg is being brought down by a chain. If the block acquires as speed of `40.0 (cm)/s` in dropping down 2.00 m ,find the work done by the chain during the process.

Explanation

Given, `m=30 kg`
`v=40 cm/sec` ltbr. `=0.4m/sec`
`S=2m` ltbr. From the free body digram the force given by the chain is
`F=(ma-mg)`
`=m(a-g)`
`[where a=acceleration of the block]`
`a=(v^2-u^2)/(2S)`
`16/(-4)=0.04m/sec^2`
so, work done `=W=FScostheta`

`=m(a-g)S cos0^0`
=30(0.04-9.8)xx2`
`=-30xx(9.76)xx2`
=585.6=-586J`
So, `W=-586J`