Question
Question: An object of mass m has angular acceleration $\alpha=0.2 \text{rad s}^{-2}$. What is the angular dis...
An object of mass m has angular acceleration α=0.2rad s−2. What is the angular displacement covered by the object after 3 second? (Assume that the object started with angle zero with zero angular velocity).

Answer
0.9 rad
Explanation
Solution
The problem asks for the angular displacement of an object undergoing constant angular acceleration.
Given:
- Angular acceleration, α=0.2 rad s−2
- Time, t=3 s
- Initial angular position, θ0=0 rad (since it started with angle zero)
- Initial angular velocity, ω0=0 rad s−1 (since it started with zero angular velocity)
We can use the kinematic equation for angular displacement under constant angular acceleration:
θ=θ0+ω0t+21αt2
Substitute the given values into the equation:
θ=0+(0)(3)+21(0.2)(3)2=0+0+21(0.2)(9)=(0.1)(9)=0.9 rad
Thus, the angular displacement covered by the object after 3 seconds is 0.9 rad.