Rotational Motion Question 191
Question: A wheel having moment of inertia $2kg-m^{2}$ about its vertical axis, rotates at the rate of 60 rpm about this axis. The torque which can stop the wheel’s rotation in one minute would be
Options:
A) 1.12Nm
B) 0.83Nm
C) 0.55Nm
D) 0.21 Nm
Show Answer
Answer:
Correct Answer: D
Solution:
[d]
$\tau \times \Delta t=I\omega $
or
$\tau \times 60=2\times 2\times 60\pi /60\Rightarrow \tau =0.21N-m$
$(\because f=60rpm\therefore \omega =2\pi f=2\pi \times \frac{60}{60})$
