The change in angular displacement as a function of time is the definition given for angular velocity, this is mathematically described as
[tex]\omega = \frac{\theta}{t}[/tex]
Here,
[tex]\theta[/tex] = Angular displacement
t = time
The angular velocity is given as
[tex]\omega = 230rev/min[/tex]
PART A) The angular velocity in SI Units will be,
[tex]\omega = 230rev/min (\frac{1min}{60s})(\frac{2\pi rad}{1rev})[/tex]
[tex]\omega = \frac{23}{3}\pi rad/s \approx 24.08rad/s[/tex]
PART B) From our first equation we can rearrange to find the angular displacement then
[tex]\theta = \omega t[/tex]
Replacing,
[tex]\theta = (24.08)(0.75)[/tex]
[tex]\theta = 18.06 rad[/tex]