Question

a balloon is ascending at the rate of 14m/s at a height of 98m above the ground when the food packet is dropped from the balloon. After how much time and with what velocity does it reach the ground? Take g=9.8m/s2

Can anyone please tell me why the value of h is negative in this question.​

Answer 1

Answer:

For the balloon,

Initial velocity, u = 14 m/s (upward)

Acceleration, a = -9.8 m/s2 (downward)

Displacement, h = -98 m (downward)

Using,

h = ut + ½ at2

=> -98 = 14t - 0.5 × 9.8 × t2

=> t = 6 s

Thus, the packet reaches the ground in 6 s.

Now, using,

v = u + at

=> v = 14 – 9.8 × 6 = -44.8 m/s (downward)

This is the velocity with which the packet reaches the ground.