Question

Автомобиль весом G = 7 кН движется по горизонтальному пути со скоростью 40 км/ч. В течение 0,5 мин автомобиль увеличивает скорость до 70 км/ч. Определить среднюю мощность, развиваемую автомобилем за указанный период времени

Answer 1

55 км средняя скорость

Answer 2

Calculation of Average Power

To calculate the average power developed by the car during the specified time period, we can use the formula:

Average Power = Work Done / Time

To find the work done by the car, we can use the formula:

Work Done = Change in Kinetic Energy

The change in kinetic energy can be calculated using the formula:

Change in Kinetic Energy = (1/2) * Mass * (Final Velocity^2 - Initial Velocity^2)

Given: - Weight of the car (G) = 7 kN - Initial velocity (v1) = 40 km/h - Final velocity (v2) = 70 km/h - Time (t) = 0.5 min

First, let's convert the given values to SI units: - Weight of the car (G) = 7 kN = 7000 N - Initial velocity (v1) = 40 km/h = 40 * (1000/3600) m/s ≈ 11.11 m/s - Final velocity (v2) = 70 km/h = 70 * (1000/3600) m/s ≈ 19.44 m/s - Time (t) = 0.5 min = 0.5 * 60 s = 30 s

Now, let's calculate the change in kinetic energy:

Change in Kinetic Energy = (1/2) * Mass * (Final Velocity^2 - Initial Velocity^2)

Since the mass of the car is not given, we cannot calculate the exact value of the change in kinetic energy or the average power. We need the mass of the car to proceed with the calculation.

Please provide the mass of the car so that we can calculate the average power developed by the car during the specified time period.