Question

When leaving a town, a car accelerates from 30 kmh-1 to 60 kmh-1 in 5 s. Assuming the

acceleration is constant, find the distance travelled in this time.
A. 6 m
B. 62.5 m
C. 41.7 m
D. 20.8 m

Answer 1

B .62.5 m

Explanation:

convert Kmh-1 in to ms-1

30 Kmh-1 = (30×1000) ÷3600 = 8.3ms-1

60 Kmh-1 = (60×1000) ÷3600 = 16.6 ms-1

acceleration = (16.6 - 8.3) ÷ 5 = 1.66 ms-2

V^2 = U^2 +2aS

(16.6)^2 = (8.3)^2 + 2×1.66 ×S

S = 62.5 m