Question

По шоссе едут легковой автомобиль массой 1 т и грузовик массой 4 т. Скорость легкового автомобиля в 3 раза больше, чем скорость грузовика? Кинетическая энергия какого автомобиля больше? Во сколько раз больше?

Answer 1

Mv²/2 - кинетическая энергия

автомобиль:1000×3v²/2=4.500×v²

грузовик:4000×v²/2=2000×v²

4500/2000=2.25 

У автомобиля больше в 2.25 раза

Answer 2

Calculation of Kinetic Energy

To determine which vehicle has a greater kinetic energy, we need to compare the kinetic energies of the car and the truck. Kinetic energy is given by the formula:

Kinetic Energy = (1/2) * mass * velocity^2

Given that the car has a mass of 1 ton (1000 kg) and a velocity 3 times greater than the truck, and the truck has a mass of 4 tons (4000 kg), we can calculate the kinetic energies of both vehicles.

Let's denote the velocity of the truck as v. Therefore, the velocity of the car is 3v.

The kinetic energy of the car is:

KE_car = (1/2) * m_car * v_car^2 = (1/2) * 1000 kg * (3v)^2 = 4500v^2

The kinetic energy of the truck is:

KE_truck = (1/2) * m_truck * v_truck^2 = (1/2) * 4000 kg * v^2 = 2000v^2

Comparison of Kinetic Energies

Comparing the kinetic energies of the car and the truck, we can see that the kinetic energy of the car is greater than the kinetic energy of the truck.

The car has a greater kinetic energy than the truck.

To determine how many times greater the kinetic energy of the car is compared to the truck, we can calculate the ratio of their kinetic energies:

KE_car / KE_truck = (4500v^2) / (2000v^2) = 2.25

Therefore, the kinetic energy of the car is 2.25 times greater than the kinetic energy of the truck.

Please note that the above calculations are based on the given information and assumptions.