Laws Of Motion Question 70
Question: A pulley fixed to the ceilling carries a string with blocks of mass m and 3 m attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration [UPSEAT 2002]
Options:
A) 0
B) $ g/4 $
C) $ g/2 $
D) $ -g/2 $
Show Answer
Answer:
Correct Answer: B
Solution:
$ a _{cm}={{( \frac{m _{1}-m _{2}}{m _{1}+m _{2}} )}^{2}}\ g={{( \frac{3m-m}{3m+m} )}^{2}}g=\frac{g}{4} $
