Answer:
640 m.
Step-by-step explanation:
The following data were obtained from the question:
Acceleration (a) = –20 m/s/s
Time (t) = 8 s
Final velocity (v) = 0 m/s
Distance (s) =.?
Next, we shall determine the initial velocity (u) of the car. This can be obtained as follow:
Acceleration (a) = –20 m/s/s
Time (t) = 8 s
Final velocity (v) = 0 m/s
Initial velocity (u)
a = (v – u) / t
–20 = (0 – u) / 8
–20 = – u / 8
Cross multiply
–20 × 8 = – u
– 160 = – u
Divide both side by – 1
u = – 160 / – 1
u = 160 m/s
Finally, we shall determine the distance travelled by the car before stopping as follow:
Time (t) = 8 s
Final velocity (v) = 0 m/s
Initial velocity (u) = 160 m/s
Distance (s) =.?
s = (v + u)t /2
s = (0 + 160) × 8 /2
s = (160 × 8) /2
s = 1280 / 2
s = 640 m
Therefore, the car travelled 640 m before stopping.