The rocket model takes off vertically upward with an acceleration of a = 4 m / s2. The engine of the model runs for 10 s.

The rocket model takes off vertically upward with an acceleration of a = 4 m / s2. The engine of the model runs for 10 s. Calculate the average speed from the start to the highest point on the trajectory.

a = 4 m / s2.
V0 = 0 m / s.

t = 10 s.

Vav -?

We express the average speed of the rocket Vav by the formula: Vav = h / t.

h = V0 * t + a * t2 / 2.

h = 0 m / s * 10 s + 4 m / s2 * (10 s) 2/2 = 200 m ..

Vav = 200 m / 10 s = 20 m / s.

Answer: the average speed of the rocket is Vav = 20 m / s.