Rotational Motion Question 77
Question: Three masses are placed on the x-axis: 300 g at origin, 500 g at $ x=40cm $ and $ 400g $ at $ x=70cm $ . The distance of the centre of mass from the origin is
[AIPMT (M) 2012]
Options:
A) 40 cm
B) 45 cm
C) 50 cm
D) 30 cm
Show Answer
Answer:
Correct Answer: A
Solution:
- $ x _{CM}=\frac{m _1x _1+m _2x _2=m _3x _3}{m _1+m _2+m _3} $ $ =\frac{300(0)+500(40)+400(70)}{300+500+400} $ $ =\frac{20000+28000}{1200} $ $ =\frac{48000}{1200} $ $ =40cm $
