Question

Помогите решить задачи!Какова скорость конькобежца массой 60 кг,если его кинетическая энергия 5070 Дж? Какова кинетическая энергия автомобиля "Запорожец" массой 740 кг,движущегося со скоростью 10 м/с?

Answer 1

Начнем с формулы
E(кинетическая)=mv^2/2
Задаче первая:
выразим скорость
v^2=2E(кинетическая)/m
v^2=2*5070/60
v^2=169
v=13м/с

Вторая задача:
E(кинетическая)=mv^2/2
Е(кинетическая)=740*10^2/2
Е(кинетическая)=37000Дж=37кДж

Answer 2

Calculation of Speed for a Speed Skater:

To calculate the speed of a speed skater, we can use the equation for kinetic energy:

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

Given that the kinetic energy (KE) of the speed skater is 5070 J and the mass (m) is 60 kg, we can rearrange the equation to solve for velocity (v):

v = sqrt(2 * KE / m)

Substituting the given values into the equation:

v = sqrt(2 * 5070 J / 60 kg)

Calculating the value:

v ≈ 13.23 m/s

Therefore, the speed of the speed skater is approximately 13.23 m/s.

Calculation of Kinetic Energy for a "Zaporozhets" Car:

To calculate the kinetic energy of a moving car, we can again use the equation for kinetic energy:

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

Given that the mass (m) of the "Zaporozhets" car is 740 kg and the velocity (v) is 10 m/s, we can substitute these values into the equation:

KE = 1/2 * 740 kg * (10 m/s)^2

Calculating the value:

KE = 1/2 * 740 kg * 100 m^2/s^2

KE = 37,000 J

Therefore, the kinetic energy of the "Zaporozhets" car is 37,000 J.