Kinematics Question 198
Question: A balloon is at a height of 81 m and it’s ascending upwards with a velocity of 12 m/s. A body of $ 2kg $ weight it’s dropped from it. If $ g=10m/s^{2} $ , the body will reach the surface of the earth in [MP PMT 1994]
Options:
A) 1.5 s
B) 4.025 s
C) 5.4 s
D) 6.75 s
Show Answer
Answer:
Correct Answer: C
Solution:
$ h=ut+\frac{1}{2}gt^{2} $
$ \Rightarrow 81=-12t+\frac{1}{2}\times 10\times t^{2}\Rightarrow t=5.4sec $