Starting the movement, the car moved for 5 seconds with an acceleration of 2 m / s ^ 2

Starting the movement, the car moved for 5 seconds with an acceleration of 2 m / s ^ 2, and then drove at a gained speed of 200 meters. Determine the average vehicle speed.

Given:

a = 2 m / s ^ 2 – initial acceleration of the vehicle;

t1 = 5 seconds – the time interval that the car was moving with acceleration a;

S2 = 200 meters is the distance that the car has traveled at a constant speed.

It is required to determine the average vehicle speed vav (m / s).

During the time of uniformly accelerated movement, the car drove the path:

S1 = a * t1 ^ 2/2 = 2 * 5 ^ 2/2 = 5 ^ 2 = 25 meters.

During this time, he picked up speed:

v = a * t = 2 * 5 = 10 m / s.

It turns out that he drove the second part of the path in the time:

t2 = S2 / v = 200/10 = 20 seconds.

Then the average speed is:

vav = Stotal / ttotal = (S1 + S2) / (t1 + t2) = (25 + 200) / (5 + 20) = 225/25 = 9 m / s.

Answer: The average vehicle speed is 9 m / s.