Question

Грузовик, имеющий массу 5т, трогается с места и , двигаясь прямолинейно и равноускоренно, проходит 10 м за 2с. Какую мощность развивает двигатель грузовика в конце разгона? 1)25кВт 2)50кВт 3)100кВт 4)250кВт 5)500кВт

Answer 1

N-мощность N=A/t

A=F*S

5т=5000кг

F=mg; F=5000*10=50000Н

N=50000*10/2=250000Вт=250кВт

Ответ:4

Answer 2

Calculation of Power Developed by the Truck's Engine

To calculate the power developed by the engine of the truck, we can use the formula:

Power (P) = Force (F) x Velocity (v)

In this case, the force can be calculated using Newton's second law of motion:

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

Given: - Mass of the truck (m) = 5 tons = 5000 kg - Distance traveled (s) = 10 m - Time taken (t) = 2 s

To find the acceleration (a), we can use the formula:

Acceleration (a) = (Change in Velocity) / Time

The change in velocity can be calculated using the formula:

Change in Velocity = Final Velocity - Initial Velocity

Since the truck starts from rest, the initial velocity is 0 m/s.

Let's calculate the acceleration first:

Change in Velocity = Distance / Time = 10 m / 2 s = 5 m/s

Now, we can calculate the acceleration:

Acceleration (a) = Change in Velocity / Time = 5 m/s / 2 s = 2.5 m/s^2

Next, we can calculate the force:

Force (F) = Mass (m) x Acceleration (a) = 5000 kg x 2.5 m/s^2 = 12500 N

Finally, we can calculate the power developed by the engine:

Power (P) = Force (F) x Velocity (v)

Since the truck travels a distance of 10 m in 2 s, the velocity can be calculated as:

Velocity (v) = Distance / Time = 10 m / 2 s = 5 m/s

Substituting the values:

Power (P) = 12500 N x 5 m/s = 62500 W = 62.5 kW

Therefore, the engine of the truck develops a power of 62.5 kW at the end of the acceleration.

So, none of the given options (25 kW, 50 kW, 100 kW, 250 kW, 500 kW) match the calculated power.