Concepts Of Physics MCQ Edition [Volume 1]PhysicsRotational Mechanics
A wheel rotating with uniform angular acceleration completes 50 revolutions in the first five seconds after starting. Determine the angular acceleration and the angular velocity at the end of five seconds.
Options
- A4 rev/s ^2, 20 rev/s
- B2 rev/s ^2, 10 rev/s
- C8 rev/s ^2, 40 rev/s
- D4 rev/s ^2, 10 rev/s
Correct answer
A. 4 rev/s ^2, 20 rev/s
Step-by-step solution
Given initial angular velocity ₀ = 0 , angular displacement = 50 rev , and time t = 5 s . Using the second equation of rotational motion: = ₀ t + 1 2 t^2 50 = 0 + 1 2 (5)^2 50 = 25 2 = 100 25 = 4 rev/s ^2 Using the first equation of rotational motion to find the angular velocity at t = 5 s : = ₀ + t = 0 + 4 5 = 20 rev/s