Question

1)Электровоз трогается с места под действием силы тяги , равной 700 кН. Какая сила трения действует на железнодорожный состав массой 3000 т, которому электровоз сообщает ускорение 0.18 м/с^2 3)Найти вес автомобиля массой 5т на середину вогнутого моста на моста в момент прохождения ее со скоростью 54км/ч. Радиус кривизны моста 500м. Чертеж желательно. Вторую не надо.

Answer 1

Ускорение из второго закона Ньютона  a=(F-T)/m, где a=0.18м/с2, F=700кН=7E5Н, T – сила трения, а m=3000т=3E6кг. Отсюда T=F-m*a=7E5-3E6*0.18=160000=160кН.
Давление автомобиля на середину вогнутого  моста равно его весу плюс центростремительной силе,  обеспечивающей движение по дуге окружности вогнутого моста. P=m*g+m*V^2/R=m*(g+V^2/R0=5000*(9.81+(54000/3600)^2/500)=51300Н. В том числе собственно вес 5000*9.81Н=49050Н, остальное - центростремительная сила

Answer 2

I'm sorry, but I'm unable to view or access search results. However, I can help you with the questions you've asked. Let's go through them one by one:

1) The force of traction exerted by the locomotive is 700 kN, and it imparts an acceleration of 0.18 m/s^2 to a train with a mass of 3000 tons. We can calculate the force of friction acting on the train using Newton's second law of motion, which states that force is equal to mass multiplied by acceleration (F = m * a).

Given: Force of traction (F) = 700 kN Mass of the train (m) = 3000 tons = 3,000,000 kg Acceleration (a) = 0.18 m/s^2

Using the formula F = m * a, we can calculate the force of friction: F = 3,000,000 kg * 0.18 m/s^2

The force of friction acting on the train is 540,000 N.

2) I'm sorry, but I couldn't find a question number 2 in your message. Could you please provide more information or rephrase the question?

3) You mentioned finding the weight of a car with a mass of 5 tons (5,000 kg) as it passes over a curved bridge with a radius of curvature of 500 m. The car is traveling at a speed of 54 km/h.

To find the weight of the car at the midpoint of the curved bridge, we need to consider the centripetal force acting on the car. The centripetal force is provided by the normal force and is equal to the weight of the car.

Given: Mass of the car (m) = 5,000 kg Speed of the car (v) = 54 km/h = 15 m/s Radius of curvature (r) = 500 m

The centripetal force (Fc) can be calculated using the formula Fc = m * v^2 / r.

Substituting the given values: Fc = 5,000 kg * (15 m/s)^2 / 500 m

The centripetal force acting on the car is 450,000 N. Since the centripetal force is equal to the weight of the car, the weight of the car at the midpoint of the curved bridge is also 450,000 N.

Unfortunately, I'm unable to provide a diagram as requested. However, I hope the explanation helps. Let me know if there's anything else I can assist you with!