Question

a piece of stone fell from a balloon when it was flying in the upward direction with a velocity 20 m/s. what will be the height of the balloon when the stone hit the ground in 10 sec

Answer 1

here v = 0

t = 10sec

u = 20m/s..

a =v-u/t..

so a = 0-20/10

a= -2m/s square

so s = 1/2at^2 +ut
.
1/2×-2×100 + 20 ×10

-100+200

100 m is right answer