A balloon at height of 81 m is moving upward with 12 m s-1. A 2 kg weight is dropped from it, the time taken by it to reach ground is

Question

A balloon at height of 81 m is moving upward with 12 m s-1. A 2 kg weight is dropped from it, the time taken by it to reach ground is (A) 1.5 s (B) 4.025 s (C) 5.4 s (D) 6.75 s.

Tardigrade Admin · Accepted Answer

Using, s = ut + (1/2) gt2, we get 81 = - 12t +(1/2) × 10 × t2 i.e. t = 5.4 s

Q. A balloon at height of $81 m$ is moving upward with $12 m s^{- 1}$ . A $2 k g$ weight is dropped from it, the time taken by it to reach ground is

1.5 s

4.025 s

5.4 s

6.75 s.

Using, $s = u t + \frac{1}{2} g t^{2}$ ,
we get 81 = $- 12 t + \frac{1}{2} \times 10 \times t^{2}$
i.e. $t = 5.4 s$

Q. A balloon at height of 81m is moving upward with 12ms−1. A 2kg weight is dropped from it, the time taken by it to reach ground is