Kinematics Question 178
Question: Two bodies of different masses $ m _{a} $ and $ m _{b} $ are dropped from two different heights $ a $ and $ b $ . The ratio of the time taken by the two to cover these distances are [NCERT 1972; MP PMT 1993]
Options:
A) $ a:b $
B) $ b:a $
C) $ \sqrt{a}:\sqrt{b} $
D) $ a^{2}:b^{2} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ h=\frac{1}{2}gt^{2}\Rightarrow t=\sqrt{2h/g} $
$ t _{a}=\sqrt{\frac{2a}{g}}and\ t _{b}=\sqrt{\frac{2b}{g}}\Rightarrow \frac{t _{a}}{t _{b}}=\sqrt{\frac{a}{b}} $