Concepts Of Physics MCQ Edition [Volume 1]PhysicsRotational Mechanics
A wheel revolves about its axis with a uniform angular acceleration. Beginning from rest, it attains 100 rev/sec in 4 seconds. Determine the angular acceleration and the angle rotated during these four seconds.
Options
- A25 rev/s ^2 and 400 rad
- B50 rev/s ^2 and 800 rad
- C25 rev/s ^2 and 200 rad
- D50 rev/s ^2 and 400 rad
Correct answer
A. 25 rev/s ^2 and 400 rad
Step-by-step solution
Initial angular velocity, ₀ = 0 Final angular velocity, = 100 rev/s Time, t = 4 s Using the first equation of rotational motion, = ₀ + t 100 = 0 + (4) = 25 rev/s ^2 Using the second equation of rotational motion, = ₀ t + 1 2 t^2 = 0 + 1 2 (25)(4)^2 = 200 rev Converting revolutions to radians: = 200 2 = 400 rad