Rankers Physics

Kinematics of Circular Motion: Practice Problem & Solution

A wheel is subjected to uniform angular acceleration about its axis. Initially its angular velocity is zero.  In the first 2 sec, it rotates through an angle θ1; in the next 4 sec, it rotates through an additional angle θ2. The ratio of θ2/θ1 is :
9
2
3
8

Solution Explained:

To solve this problem, we apply the core principles of Kinematics of Circular Motion. Understanding the underlying formula is key to arriving at the correct answer below:

For Circular motion angle traversed is θ = ω t + ½ α t²

so, θ1   =½α(2)² = 2α

and θ1 + θ2 = ½α(6)² = 18 α ⇒ θ2= 16 α

so θ2 /θ1= 8

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