An automobile driver puts on the brakes and decelerates from 30.0 m/s to zero in 12.0 s.What distance does the car travel?
A) 150 m
B) 180 m
C) 360 m
D) 750 m

Question

Quizplus · Accepted Answer

We can use the formula: 
$$d=\frac{1}{2}(v_i+v_f)t$$
where $d$ is the distance, $v_i$ is the initial velocity, $v_f$ is the final velocity, and $t$ is the time. 
Plugging in the given values, we have:
$$d=\frac{1}{2}(30.0+0)\cdot12.0=180	ext{ m}$$
Therefore, the best choice is B, which corresponds to 180 m.

An Automobile Driver Puts on the Brakes and Decelerates from 30.0