Sleds weighing 3 kg by the end of the descent from the mountain acquired a speed

Sleds weighing 3 kg by the end of the descent from the mountain acquired a speed of 10 m / s and continued to move straight along the horizontal surface. How long did the sled move horizontally and what path did it go if the acting frictional force was 2 H.

m = 3 kg.

V0 = 10 m / s.

V = 0 m / s.

F = 2 N.

t -?

S -?

According to Newton’s 2 law, the acceleration of a body is directly proportional to the force F, which acts on the body, and is inversely proportional to the mass of the body m: a = F / m.

According to the definition, the acceleration of a body, a shows how quickly the body’s velocity V changes over time t and is determined by the formula: a = (V0 – V) / t.

a = (10 m / s – 0 m / s) / t.

F / m = (V0 – V) / t.

The braking time will be determined by the formula: t = (V0 – V) * m / F.

t = (10 m / s – 0 m / s) * 3 kg / 2 N = 15 s.

a = (10 m / s – 0 m / s) / 15 s = 0.66 m / s ^ 2.

The path S of the sleigh on the horizontal surface is found by the formula: S = V0 ^ 2/2 * a.

S = (10 m / s) ^ 2/2 * 0.66 m / s ^ 2 = 75.8 m.

Answer: the sled will stop after a time t = 15 s and pass the path S = 75.8 m.