Question

When a ceiling fan is switched on, it makes 10 rotations in the first 3 second. How many rotations will it makes in the next 3 seconds? (Assume uniform angular acceleration)

• A. 10
• B. 20
• C. 30
• D. 40

Answer 1

Answer: (C)

30

Answer 2

Apply q = w₀t +$\frac{1}{2}$a t²

If w₀ = 0

For first three sec. q = $\frac{1}{2}$a(3)²

For total six sec. q = $\frac{1}{2}$a(6)²