Question

A gallon starts rising from the ground from rest with an upward acceleration 2m/s^2. Just after 1s, a stone is dropped from it. The time taken by stone to strike the ground is nearly

1) 0.3s

2) 0.7s

3) 1s

4) 1.4s

Answer 1

i'm guessing a "balloon"?

at t=1s ... the balloon has an upward velocity of 2 m/s
... the height of the balloon is 1 m ... average velocity of 1 m/s for 1 s

the free-fall equation is ... h = 1/2 g t^2 + 2 t + 1
... solve the equation for h = 0 ... stone on the ground
... remember, g is -9.8 m/s^2