Question

Поезд массой 400 тонн движется со скоростью 40 км/ч и после торможения останавливается. Какова сила торможения если тормозной путь поезда равен 200м ? Помогите!

Answer 1

Кинетическая энергия поезда m*V^2/2
Работа силы торможения F*S
По закону сохранения энергии m*V^2/2=F*s
F=m*V^2/2*S=400*10^3*11,1^2/2*200=123*10^3 H

Answer 2

Calculation of the Braking Force

To calculate the braking force of the train, we can use the formula:

Braking Force = (Mass of the Train * Change in Velocity) / Stopping Distance

Given: - Mass of the train = 400 tons = 400,000 kg - Initial velocity = 40 km/h = 40,000 m/3600 s = 11.11 m/s - Final velocity = 0 m/s - Stopping distance = 200 m

Using the formula, we can calculate the braking force:

Braking Force = (400,000 kg * (0 m/s - 11.11 m/s)) / 200 m

Let's calculate the value:

Braking Force = (400,000 kg * (-11.11 m/s)) / 200 m

Braking Force = -2,222,000 N

Therefore, the braking force of the train is approximately -2,222,000 N.

Please note that the negative sign indicates that the force is acting in the opposite direction to the motion of the train, which is necessary for braking.