Question

A car whose acceleration is constant reaches a speed of

80 km/h in 20 s starting from rest. How much more time
is required for it to reach a speed of 130 km/h?

Answer 1

12.5s

Explanation:

Answer 2

12.5 s

Explanation:

If acceleration is constant, speed is proportional to time. To increase the speed by 50 km/h, the car will need an additional time given by ...

t/(50 km/h) = (20 s)/(80 km/h)

t = (20 s)(50/80) . . . . . multiply by 50 km/h

t = 12.5 s

It will take 12.5 more seconds for it to reach a speed of 130 km/h.