A block of mass 2 kg is being brought down by a string. If the block acquires a speed `1(m)//(s)` in dropping down 25 cm, find the work done by the string in the process.

Explanation

`v^2=u^2+2as`
`1^2=0+2axx(1)/(4)impliesa=2(m)/(s^2)`
`20-T=2a=2xx2`
`T=16N`
Work done by the string
`W=-T_S=-16xx(1)/(4)`
The string does negative work.