Question

during the spin dry cycle of a washing machine, the motor slows from 90 rad/s to 30 rad/s while turning the drum though an angle of 180 radians. what is the magnitude of the angular acceleration of the motor?a 64 rad/s^2b 32 radc 10 radd 20 rade 1.0 rad

Answer 1

Answer:

option D

Explanation:

given,

initial speed of motor, ω₁ = 90 rad/s

final speed of motor, ω₂ = 30 rad/s

angle, θ = 180 rad

angular acceleration,α = ?

using equation of rotational motion

 ω₂² = ω₁ ² + 2 α θ

  90² = 30² + 2 x α x 180

     360 α = 7200

     α = 20 rad/s²

the angular acceleration of the motor comes out to  be 20 rad/s²

the correct answer is option D