Question

The angular speed of a flywheel moving with uniform angular acceleration changes from 1200 rpm to 3120 rpm in 16 seconds. The angular acceleration in rad/s2 is:

• A. $2\pi$
• B. $4\pi$
• C. $12\pi$
• D. $104\pi$

Answer 1

Answer: (B)

$4\pi$

Answer 2

We have two rotational velocities:
$ω_1$, which is 1200 revolutions per minute, and $ω_2$, which is 3120 revolutions per minute.
We also know that the time it takes for the rotation to go from $ω_1$ to $ω_2$ is 16 seconds.
Using this information, we can calculate the angular acceleration $(\alpha)$ of the rotation as follows:

$\alpha = [\frac{(ω_2 - ω_1)}{t}] \times [\frac{2\pi}{60}]$
$\alpha = [\frac{(3120 - 1200)}{16}] \times [\frac{2\pi}{60}]$
$\alpha = (\frac{1920}{16}) \times (\frac{2\pi}{60})$
$\alpha = 4\pi$

Therefore, the angular acceleration is 4π radians per second squared.