Question

Constant Angular Acceleration in the Kitchen Dario a prep cook at an Italian restaurant, spins a salad spinner and observes that it rotates 20.0 times in 5 00 seconds and then stops spinning it. The salad spinner rotates 6.00 more times before it comes to rest. Assume that the spinner slows down with constant angular acceleration. What is the magnitude of the angular a Express your answer numerically in radians per second per second. The question will be shown alter you complete previous

Answer 1

This is an exercise of rotational kinematics, we write the expressions

w_e²= w_o²_–2α θ

Data

θ1 = 20 rev (2π rad/1 rev) = 40π rad

t1 = 5 s

θ2 = 6 rev ( 2π rad/1 rev) = 12π rad

w_e = 0

We begin calculating the initial angular velocity

w_o= θ1/t1

w_o= 40π / 5

w_o= 8π rad/s

calculate in the expression

0 = w_o² – 2 α θ2

α = w_o²/ 2 θ2

α = ( 8π)²/ (2 12π )

α = 8π/3

α = 8.38 rad/s²