A car with a mass of 1500 kg, moving at a speed of 80 km / h, stops under the influence of the braking force F

| March 7, 2021 | education

A car with a mass of 1500 kg, moving at a speed of 80 km / h, stops under the influence of the braking force F during time t, while traveling at the same time a distance of 50 m. find unknown quantities.

m = 1500 kg.

V0 = 80 km / h = 22.22 m / s.

V = 0 m / s.

S = 50 m.

Ftorm -?

t -?

When braking, the braking force Fstorm is found according to 2 Newton’s laws: Fstorm = m * a.

We express the acceleration of the car by the formula: a = (V0 ^ 2 -V ^ 2) / 2 * S.

Since V = 0 m / s, then a = V0 ^ 2/2 * S.

Ftorm = m * V0 ^ 2/2 * S.

Ftorm = 1500 kg * (22.22 m / s) ^ 2/2 * 50 m = 7406 N.

Let us write down the definition for the acceleration of the body: a = (V0 – V) / t.

Since V = 0 m / s, then a = V0 / t.

t = V0 / a = V0 * 2 * S / V0 ^ 2 = 2 * S / V0.

t = 2 * 50 m / 22.22 m / s = 4.5 s.

Answer: Ftorm = 7406 N, t = 4.5 s.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.