To find the angular acceleration of a rotating wheel, we can use the formula:
Angular Acceleration Formula
The formula for angular acceleration (α) is:
α = (ω_f - ω_i) / t
where:
- ω_f = final angular velocity
- ω_i = initial angular velocity
- t = time in seconds
Convert RPM to Radians per Second
First, we need to convert the angular speeds from revolutions per minute (rpm) to radians per second (rad/s):
- ω_i = 1800 rpm = 1800 × (2π rad / 1 rev) × (1 min / 60 s) = 60π rad/s
- ω_f = 3000 rpm = 3000 × (2π rad / 1 rev) × (1 min / 60 s) = 100π rad/s
Calculate Angular Acceleration
Now, substituting the values into the angular acceleration formula:
α = (100π rad/s - 60π rad/s) / 20 s
α = (40π rad/s) / 20 s = 2π rad/s²
Final Answer
The angular acceleration is 2π rad/s², which corresponds to option C.