Question

A Body is dropped from a certain height h ( h is very large) and second body is thrown downward with velocity of 5m/s simultaniously.what will be differenece in height of two bodies after 3s

Answer 1

therefore difference in height is 15

Answer 2

Note: The height 'h' is given very large which means none of the body reaches the ground in 3 s.
Now let us solve the numerical.
Body A is dropped from height h, so the distance travelled by the body A in 3 s,
sA=uAt+12gt2⇒sA=12gt2 ...(1)The body B is thrown downward with velocity 5 m/s.The distance travelled by the body B in 3 s,sB=uBt+12gt2⇒sB=5×3+12gt2=15+12gt2 ...(2)Therefore, height of body A after 3 shA=h-sA ...(3)Height of body B after 3 s,hB=h-sB ...(4)Therefore, the difference between their heights=hA-hB=h-sA-(h-sB)=sB-sA=15+12gt2-12gt2=15 m