Question

Определите полную механическую энергию стрелы массой 200 г, летящей со скоростью 20м/с на высоте 10м

Answer 1

Дано:
m=200г=0,2 кг
h=10 м
V=20 м/с
Найти:Е
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Решение.
Полная механическая энергия= Кинетическая энергия (Eк)+Потенциальная энергия (Ep).
Е=Ек+Ер
Ек=mV^2/2
Ep=mgh
E=mV^2/2 +mgh
E=(0,2 кг*(20 м/с)^2/2+0.2 кг*10м/с^2*10м= 40+20=60 Дж
Ответ: 60 Дж.

Answer 2

Calculation of the Total Mechanical Energy of an Arrow

To determine the total mechanical energy of an arrow, we need to consider both its kinetic energy and potential energy.

The kinetic energy (KE) of an object is given by the formula:

KE = (1/2) * m * v^2

where: - KE is the kinetic energy - m is the mass of the object - v is the velocity of the object

The potential energy (PE) of an object at a certain height is given by the formula:

PE = m * g * h

where: - PE is the potential energy - m is the mass of the object - g is the acceleration due to gravity (approximately 9.8 m/s^2) - h is the height of the object

To calculate the total mechanical energy (E) of the arrow, we can add the kinetic energy and potential energy:

E = KE + PE

Let's calculate the total mechanical energy of the arrow with the given values:

- Mass of the arrow (m) = 200 g = 0.2 kg - Velocity of the arrow (v) = 20 m/s - Height of the arrow (h) = 10 m

Using the formulas mentioned above, we can calculate the kinetic energy and potential energy of the arrow:

KE = (1/2) * m * v^2 = (1/2) * 0.2 * 20^2 = 40 J PE = m * g * h = 0.2 * 9.8 * 10 = 19.6 J Now, let's calculate the total mechanical energy:

E = KE + PE = 40 J + 19.6 J = 59.6 J

Therefore, the total mechanical energy of the arrow with a mass of 200 g, flying at a velocity of 20 m/s, and at a height of 10 m is 59.6 Joules.