# Sleds roll down the mountain within 12 seconds. With what acceleration did they move

**Sleds roll down the mountain within 12 seconds. With what acceleration did they move and what is their speed at the end of the slope, if its length is 36 m?**

t = 12 s.

S = 36 m.

V0 = 0 m / s.

a -?

V -?

When moving with constant acceleration, the distance traveled S is determined by the formula: S = V0 * t + a * t ^ 2/2, where V0 is the initial speed of the movement, t is the time of movement, a is the acceleration of the sleigh.

Since the initial speed of the sled is V0 = 0 m / s, the formula will take the form: S = a * t ^ 2/2.

a = 2 * S / t ^ 2.

a = 2 * 36 m / (12 s) ^ 2 = 0.5 m / s2.

The acceleration of a body a is called a vector physical quantity, which shows how the body’s velocity V changes over time t: a = (V – V0) / t.

Since the initial speed of the sled is V0 = 0 m / s, the formula will take the form: a = V / t.

V = a * t.

V = 0.5 m / s2 * 12 s = 6 m / s.

Answer: the acceleration of the sled was a = 0.5 m / s2, the speed of the sled at the end of the descent will be V = 6 m / s.