A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?
A) 400 m
B) 300 m
C) 200 m
D) 100 m
E) none of these

Question

Quizplus · Accepted Answer

The automobile's acceleration is (40 m/s - 20 m/s) / 10 s = 2 m/s². Using the formula for distance under uniform acceleration, $ s = ut + \frac{1}{2}at^2 $, where $ u = 20 $ m/s, $ a = 2 $ m/s², and $ t = 10 $ s, the distance $ s = 20 \times 10 + \frac{1}{2} \times 2 \times 10^2 = 200 + 100 = 300 $ m.

A 1000-Kg Automobile Enters a Freeway On-Ramp at 20 M/s