The initial velocity of the stone was 25 ft/ sec up, Vo = 25 ft/s up ↑, and g is acceleration due to gravity =
32.2 ft/s2↓ , and t = 8 s
The final velocity is Vf = -gt + Vo = -32.2 ft/s2(8 s) + 25 ft/sec = -232.6 ft/s ↓ s the velocity when the ball hits the ground. The -ve sign indicates downward direction same as in acceleration g ↓
The height of the balloon when the stone was dropped is:
y = -1/2 gt2 + Vo t + yo , here yo = 0 initial height of balloon is not known
y = -1/2 ( 32.2 ft/s2)(8 s)2 + ( 25 ft/s)(8 s)= -830.4 ft ↓ with the negative sign indicating downward direction for height or 830.4 ft above ground
