Q.

If the total energy transferred to a surface in time t is 6.48×109J, then the magnitude of the total momentum delivered to this surface for complete absorption will be   [2024]

1 2.46×10-3kgm/s  
2 2.16×10-3kgm/s  
3 1.58×10-3kgm/s  
4 4.32×10-3kgm/s  

Ans.

(2)

Energy transferred in time 't'=6.48×105J

PowerP=6.48×105t

For complete absorption

Pressure=IC=Energyt.A.C

(Pressure×A)=Energytime×C

Force=Energytime×C

Change in momentum=Energytime×C

So Momentum delivered=EnergyC

=6.48×1053×108=2.16×10-3 kg m/s