A bird flies at 10ms\(^{-1}\) for 3s, 15ms\(^{-1}\) for 3s and 20 ms\(^{-1}\) for 4s. Calculate the bird’s average speed
- 4.5 ms-1
- 15.0 ms-1
-
15.5 ms-1
- 51.7 ms-1
The correct answer is: C
Explanation
Av. speed = \(\frac{3 \times 15 + 3 \times 10 + 4 \times 20}{3 + 3 + 4}\)
= 15.5 ms\(^{-1}\)