Question

ПОЖАЛУЙСТА ПОМОГИТЕ УМОЛЯЮ Найти изменения кинетической энергии автомобиля массой 2 тонны при торможении, если начальная скорость 20 м/с

Answer 1

Eк1 = (m/2)*(v^2),
m = 2000кг, v = 20м/с,
Eк2 = (m/2)*0 = 0
ΔEк = Ек2 - Ек1 = -(m/2)*(v^2) = -(2000кг/2)*(20м/с)² = -1000*400Дж = 
=-400кДж,
Знак минус показывает, что кинетическая энергия уменьшилась, убыль кинетической энергии составляет 400кДж.

Answer 2

Calculation of Changes in Kinetic Energy

To calculate the changes in kinetic energy of a car during braking, we need to consider the initial velocity, final velocity, and the mass of the car. In this case, the car has a mass of 2 tons (2000 kg) and an initial velocity of 20 m/s.

The formula to calculate the change in kinetic energy is:

Change in Kinetic Energy = 1/2 * mass * (final velocity^2 - initial velocity^2)

Let's plug in the values:

Change in Kinetic Energy = 1/2 * 2000 kg * ((0 m/s)^2 - (20 m/s)^2)

Simplifying the equation:

Change in Kinetic Energy = 1/2 * 2000 kg * (-400 m^2/s^2)

Change in Kinetic Energy = -400,000 Joules

Therefore, the change in kinetic energy of the car during braking is -400,000 Joules. The negative sign indicates a decrease in kinetic energy, which is expected during braking.

Please note that the negative sign indicates a decrease in kinetic energy, which is expected during braking.