Question

Jane is riding in a hot air balloon that is rising vertically at a constant speed of 3 m/s over a lake. She drops a rock from the balloon when the distance from the rock to the water is 50 m. Use g m/s^2, and let the up direction be positive. How long after Jane drops the rock will it splash into the water?

Answer 1

It is given that up direction be positive.

Ball velocity at the time is was dropped is 3 m/s.

g = -9.8 m/s²

s = -50 m

Now, using equation of motion for time :

s = ut + at²/2

3t - 4.9t² + 50 = 0

4.9t² - 3t - 50 = 0

Solving above equation, we get :

t = 3.52 s

Therefore, the rock will splash into the water after 3.52 s.