Laws Of Motion Question 135
Question: A light string passing over a smooth light pulley connects two blocks of masses $ m _{1} $ and $ m _{2} $ (vertically). If the acceleration of the system is g/8, then the ratio of the masses is
Options:
A) 8 : 1
B) 9 : 7
C) 4 : 3
D) 5 : 3
Show Answer
Answer:
Correct Answer: B
Solution:
[b] From F.B.D. of $ m _{1}:T-m _{1}g=m _{1}a $ (i) From F.B.D. of $ m _{2}:m _{2}g-T=m _{2}a $ (ii) From (i) and (ii), $ a=( \frac{m _{2}-m _{1}}{m _{1}+m _{2}} )g $
$ \Rightarrow \frac{g}{8}=( \frac{m _{2}-m _{1}}{m _{1}+m _{2}} )g\Rightarrow \frac{m _{2}}{m _{1}}=\frac{9}{7} $
