A wooden block is dropped from a tower of height 200 m. Simultaneously a bullet is fired from the foot of the tower aiming the block with the velocity of 100ms−1 . Given that the masses of both the block and the bullet , each equal to 100 g and the bullet is embedded in the block, find the maximum potential energyof the system of the block and the bullet. (g=10ms−2) (Neglect the time of impact).
MBlock=100gMBullet=100g
initial
S1+S2=200M12gt2+100t−12gt2=200t=2secS1=20MS2=180M
At point P V of system is
AtpointPVofsystemis(200g)V=(100g)[20](^j)+(100g)(80^j)200gV^j=60(100g)^jV=30m/s
After the impact energy will remain conserved
PEj+KEj=PEf+KEf2001000×10×180+12×2001000×900=PEf360+90=PEfPEf=450J