Question

Find average velocity in the time interval 0 to the time when velocity becomes zero?

• A. $113.75rad{s}^{-1}$
• B. $143.25rad{s}^{-1}$
• C. $162.5rad{s}^{-1}$
• D. none

Answer 1

Answer: (C)

$162.5rad{s}^{-1}$

We have initial displacement as

$\theta \left(0\right)=0$

And final angular displacement as

$\frac{d\theta }{dt}=0$

$t=0.7$
$\theta \left(0.7\right)=250\left(0.7\right)-20(0.7{)}^2-150(0.7{)}^3$
$=175-9.8-51.45=113.75$
The average velocity is thus given as
${\omega }_{av}=\frac{\theta \left(0.7\right)-\theta \left(0\right)}{0.7}$
${\omega }_{av}=\frac{(113.75-0)}{0.7}=162.5rad{s}^{-1}$