A truck travelling at 50 kph. It brakes retarding it at 5 m/sec. How long it will take up to stop the truck? What distance reached it when it finally stop?
assume you mean 5 m/s^2
50 *1000/3600 = 13.9 m/s
v = 13.9 - 5 t
0 = 13.9 - 5 t
t = 13.9/5
average speed during stop = 13.9/2
d = (13.9/2) (13.9/5)
or
d = Vi t - .5 (5) t^2
d =13.9(13.9/5)-.5 (5) (13.9^2)/5^2
= .5 *13.9^2/5 the same