Question

A ballooon is going vertically upward with a velocity of 15 ms-1. When it is at height of
50 m above the ground a stone is dropped from it. The stone will reach the ground in time
(g = 10ms-2)
(A) 7 sec
(B) 6 sec
(C) 5 sec
(D) 9 sec​

Answer 1

Step-by-step explanation:

hope this helps you to understand

Answer 2

Answer:

Total time taken = 5 seconds

Step-by-step explanation:

∵ You throw the stone from balloon rising upward then the velocity of balloon is equal to initial velocity of stone .

The stone must travel some distance upward before falling downward .

At highest point,

• Final velocity (V) = 0 m/s

• Acceleration (g) = -10 m/s²

• Initial velocity (U) =15 m/s

V² = U²– 2gh

∴ h= 11.25 m

g = (V - U)/ T₁

∴ T₁ = 1.5 sec .

When stone is falling downward ,

• Total height (H) = 50 + 11.25 = 61.25 m

• Initial velocity (U) = 0 m/s

• Acceleration = g = 10 m/s²

Let time taken be T₂

H = UT₂ + 0.5 gT₂²

∴ T₂ = 3.5 sec

∴ The total time taken by stone to reach ground,

T = T₁ + T₂ = 1.5 + 3.5 = 5 seconds

∴ Total time taken = 5 seconds