Question

1. Вертолет массой 7 травномерно приземляется со скоростью 36 км/ч. Чему равна его полная механическая энергия на высоте 500 м? ​

Answer 1

Ответ: 35,4МДж

Объяснение:

Дано:

m=7т=7000кг

V=36км/ч=10м/с

h=500м

g=10Н/кг

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Е-?

Е=Ек+Еп=mV²/2+mgh=m(V²/2+gh)=7000*(10²/2+10*500)=35350000Дж=35,4МДж

Answer 2

Calculation of Total Mechanical Energy

To calculate the total mechanical energy of the helicopter at a height of 500 m, we need to consider both its kinetic energy and potential energy.

Kinetic Energy (KE): The kinetic energy of an object is given by the formula KE = (1/2)mv^2, where m is the mass of the object and v is its velocity.

Given that the mass of the helicopter is 7 t (tonnes) and its velocity is 36 km/h, we need to convert the mass and velocity to SI units before calculating the kinetic energy.

Converting the mass of the helicopter from tonnes to kilograms: 1 t = 1000 kg Therefore, the mass of the helicopter is 7 t * 1000 kg/t = 7000 kg.

Converting the velocity of the helicopter from km/h to m/s: 1 km/h = (1000 m / 3600 s) m/s Therefore, the velocity of the helicopter is 36 km/h * (1000 m / 3600 s) = 10 m/s.

Now we can calculate the kinetic energy: KE = (1/2) * 7000 kg * (10 m/s)^2

Potential Energy (PE): The potential energy of an object at a height h is given by the formula PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height.

Given that the height of the helicopter is 500 m, we can calculate the potential energy: PE = 7000 kg * 9.8 m/s^2 * 500 m

Total Mechanical Energy (E): The total mechanical energy is the sum of the kinetic energy and potential energy: E = KE + PE

Now let's calculate the total mechanical energy of the helicopter at a height of 500 m.

Calculation:

Kinetic Energy (KE): KE = (1/2) * 7000 kg * (10 m/s)^2

Potential Energy (PE): PE = 7000 kg * 9.8 m/s^2 * 500 m

Total Mechanical Energy (E): E = KE + PE

Answer:

The total mechanical energy of the helicopter at a height of 500 m is the sum of its kinetic energy and potential energy, which can be calculated as follows:

KE = (1/2) * 7000 kg * (10 m/s)^2 = 350,000 J

PE = 7000 kg * 9.8 m/s^2 * 500 m = 34,300,000 J

E = KE + PE = 350,000 J + 34,300,000 J = 34,650,000 J

Therefore, the total mechanical energy of the helicopter at a height of 500 m is 34,650,000 Joules.