InterviewSolution
Saved Bookmarks
| 1. |
When a ceiling fan is switched on, it makes 10 rotations in the first 3 seconds. How many rotations will it make in the next 3 seconds? (Assume uniform angular acceleration.) (a) 10 (b) 20 (c) 30 (d) 40 |
|
Answer» Correct Answer: (c) 30 θ = 2πn = ωit + 1/2 at2 or 2π x 10 = 1/2 a(3)2 or a = 40π / 9. Let it make N rotations in the first 6 seconds. 2πN = 1/2 a (6)2 or N = 1/2π . 36/2 .40π/9 = 40 ∴ the required number of rotations = 40 - 10 = 30. |
|