Kinematics Question 545
Question: A weightless thread can bear tension upto 3.7 kg wt. A stone of mass 500 gms it’s tied to it and revolved in a circular path of radius 4 m in a vertical plane. If $ g=10m{{s}^{-2}} $ , then the maximum angular velocity of the stone will be[MP PMT/PET 1998]
Options:
A) 4 radians/sec
B)16 radians/sec
C) $ \sqrt{21} $ radians/sec
D) 2 radians/sec
Show Answer
Answer:
Correct Answer: A
Solution:
Max. tension that string can bear = 3.7 kgwt = 37N
Tension at lowest point of vertical
$ \text{loop}=mg+m{{\omega }^{2}}r $ = $ 0.5\times 10+0.5\times {{\omega }^{2}}\times 4=5+2{{\omega }^{2}} $ \ 37 = 5 + 2w2 therefore w = 4 rad/s.
