Kinematics Question 409
Question: A stone falls freely under gravity. It covers distances $ h _{1},h _{2} $ and $ h _{3} $ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between $ h _{1},h _{2} $ and $ h _{3} $ it’s
Options:
A) $ h _{1}=\frac{h _{2}}{3}=\frac{h _{3}}{5} $
B) $ h _{2}=3h _{1}andh _{3}=3h _{2} $
C) $ h _{1}=h _{2}=h _{3} $
D) $ h _{1}=2h _{2}=3h _{3} $
Show Answer
Answer:
Correct Answer: A
Solution:
$ \therefore h=\frac{1}{2}gt^{2}\text{ }\therefore {{h} _{1}}=\frac{1}{2}g{{( 5 )}^{2}}=125 $
$ {{h} _{1}}+{{h} _{2}}=\frac{1}{2}g{{( 10 )}^{2}}=500\Rightarrow {{h} _{2}}=375 $
$ \therefore {{h} _{1}}+{{h} _{2}}+h _{3}=\frac{1}{2}g{{( 15 )}^{2}}=1125 $
$ \Rightarrow h _{3}625 $
$ h _{2}=3h _{1},h _{3}=5h _{1}\text{ or }{{h} _{1}}=\frac{h _{2}}{3}=\frac{h _{3}}{5} $
