The rotor of an electric motor rotates at the constant rate ω1 =1900 rpm. determine the angular acceleration of the rotor as the motor is rotated about the y axis with a constant angular velocity ω2 of 6 rpm counterclockwise when viewed from the positive y axis.

Angular acceleration =Ф°

Explanation:

Here angular velocity is combination of two types of rotation

Using cylindrical coordinates( r°=radial unit vector;Ф°=angular unit vector)

ω=1900*  r° +6 z

Δω= Δ(  r°) +Δ (6z)

as Δr =(ΔФ) Ф°  ; Δz=0

Δω=   (ΔФ) Ф°

Δω/Δt =  (ΔФ/Δt)Ф°

as we know ΔФ/Δt is about positive y axis

ΔФ/Δt =6rpm =6* =

Δω/Δt = ()()Ф°

angular acceleration =Ф°

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s