Calculate the angular velocity and linea­r velocity of both wheels assuming the l­arger wheel rotates at 120 revolutions p­er min (20rpm)

120 revolutions p­er min is (20RPM)
120revolutions is 240 Pi radians (because 1 revolution is 2Pi rad)

angular velocity
w= 240Pixf, f is the frequency and f= 1/T, T =1mn=60s=period, so f=1/60=0.01Hz
so w = 240*Pi*0.01=12.56 rad /s
linear velocity can be found with
V =Rx w,    
V=12.56 R the value depends on what value is the radius of both wheels

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