Final answer:
The angular acceleration of the washer is 1.5 rad/s², the angular displacement during the 20 s interval is 400 rad, and the average angular speed is 25 rad/s.
Step-by-step explanation:
The student's question asks about the angular motion of a washer that changes its angular velocity from 10 rad/s to 40 rad/s in 20 s. This encompasses calculating the angular acceleration, angular displacement, and average angular speed of the washer during this process. These are concepts from the Physics subject, specifically dealing with rotational motion.
Angular Acceleration
To find the angular acceleration (α), we use the formula α = (ω - ω0)/t, where ω is the final angular velocity, ω0 is the initial angular velocity, and t is the time period. The washer's angular acceleration is ((40 rad/s) - (10 rad/s)) / (20 s), which equals 1.5 rad/s².
Angular Displacement
The angular displacement (Θ) can be calculated using the equation Θ = ω0t + 0.5*α*t². Plugging in our values, we get 10 rad/s * 20 s + 0.5 * 1.5 rad/s² * (20 s)², resulting in an angular displacement of 400 rad.
Average Angular Speed
The average angular speed (ωavg) is given by the formula ωavg = (ω + ω0)/2. The average angular speed for the washer is (40 rad/s + 10 rad/s) / 2, yielding an average angular speed of 25 rad/s.