Question

A body of mass 2kg is thrown vertically upwards with an initial velocity of 20m/s what will be its potential energy at the end of 2s

Answer 1

on applying time of flight =2u/g u total time of flight =4sec then by time of accent=time of descent at 2 sec object is on its max height.
at Max Height final velovity becomes 0.then by applying v^2-u^2=2as u get ur height that is 1 metre by applying PE= mgh u get ur answer is 20 joules