Question

Пожалуйсто полностью решение!!!!Трамвай массой 20т через 2 сек после начала движения по горизонтальному пути развивает скорость 10,8км/ч. Определить ускорение вагона и мощность развивается его моторами

Answer 1

A=(V-V0)/t=(3-0)/2=1,5 м/с2
m*V^2/2=N*t
N=m*V^2/2*t=20 000*9/2*2=45 000 Вт=45 кВт

Answer 2

Problem Statement

We are given that a tram with a mass of 20 tons starts moving on a horizontal track and reaches a speed of 10.8 km/h after 2 seconds. We need to determine the acceleration of the tram and the power developed by its motors.

Solution

To find the acceleration of the tram, we can use the formula:

Acceleration (a) = Change in velocity (Δv) / Time (t)

The change in velocity can be calculated by converting the final speed from km/h to m/s and subtracting the initial velocity, which is assumed to be zero since the tram starts moving from rest. The time is given as 2 seconds.

To find the power developed by the motors, we can use the formula:

Power (P) = Force (F) × Velocity (v)

The force can be calculated using Newton's second law of motion:

Force (F) = Mass (m) × Acceleration (a)

The mass of the tram is given as 20 tons, which we need to convert to kilograms.

Let's calculate the acceleration and power:

1. Convert the mass of the tram from tons to kilograms: - 1 ton = 1000 kilograms - Mass (m) = 20 tons × 1000 kilograms/ton = 20000 kilograms

2. Convert the final speed from km/h to m/s: - 1 km/h = 1000 m/3600 s - Final speed (v) = 10.8 km/h × 1000 m/3600 s = 3 m/s

3. Calculate the acceleration: - Acceleration (a) = (Final speed - Initial speed) / Time - Initial speed is assumed to be zero since the tram starts from rest. - Acceleration (a) = (3 m/s - 0 m/s) / 2 s = 1.5 m/s^2

4. Calculate the force: - Force (F) = Mass × Acceleration - Force (F) = 20000 kg × 1.5 m/s^2 = 30000 N

5. Calculate the power: - Power (P) = Force × Velocity - Power (P) = 30000 N × 3 m/s = 90000 W

Therefore, the acceleration of the tram is 1.5 m/s^2 and the power developed by its motors is 90000 W.