Question

a body of mass 3 kg is under a constant force which causes a displacement s in metere in it , given by the relation s =1÷3t,where t is in second. work done by the force in 2 s is

Answer 1

s=13s=13t2=>dsdt=23t2=>dsdt=23ttacceleration =a=d2sdt2=a=d2sdt2=23=23m/s2m/s2Force =m×a=m×a=3×23=3×23=2N=2Nds=23ds=23tdttdtWork done =∫Fds=∫FdsW=F∫0t23W=F∫0t23tdttdt=2×23=2×23×t22∣∣20×t22|02=43×42=43×42=83=83J