Question

1. Снаряд массои 30 кг вылетел из ствола орудия со скоростью 800 м/с под углом к горизонту. В момент падения на землю скорость снаряда была 600 м/с. Место приземления снаряда оказалось на 50 м ниже, чем место выстрела. Дальность полёта составила 10 км. Какую (по модулю) работу совершила сила сопротивления воздуха? 1 3015 кДж 2 4200 кДж 3 4215 кДж Справочные данные Ускорение свободного падения, g=10 м/с 2

Answer 1

Ответ:

3:3015 кДж

Объяснение:

надеюсь что правильно

Answer 2

Given Information:

- Mass of the projectile: 30 kg - Initial velocity of the projectile: 800 m/s - Angle of projection with respect to the horizontal: unknown - Final velocity of the projectile at the moment of impact: 600 m/s - Vertical displacement of the projectile: -50 m (below the initial position) - Range of the projectile: 10 km - Acceleration due to gravity: 10 m/s^2

Calculating the Angle of Projection:

To calculate the angle of projection, we need to use the given information about the initial and final velocities of the projectile. We can use the following equation to find the angle:

Final Velocity^2 = Initial Velocity^2 + 2 * g * Vertical Displacement

Substituting the given values:

600^2 = 800^2 + 2 * 10 * (-50)

Simplifying the equation:

360,000 = 640,000 - 1,000

1,000 = 640,000 - 360,000

1,000 = 280,000

Taking the square root of both sides:

√1,000 = √280,000

31.62 = 529.15

Therefore, the angle of projection is approximately 31.62 degrees.

Calculating the Work Done by Air Resistance:

To calculate the work done by air resistance, we need to find the force of air resistance acting on the projectile and then multiply it by the distance traveled.

The force of air resistance can be calculated using the equation:

Force of Air Resistance = 0.5 * Air Density * Cross-sectional Area * Coefficient of Drag * Velocity^2

However, we do not have the values for air density, cross-sectional area, and coefficient of drag. Therefore, we cannot calculate the exact force of air resistance.

However, we can make an estimation by assuming a typical value for the coefficient of drag, which is around 0.5 for a projectile. We can also assume a constant air density of 1.2 kg/m^3.

Using these assumptions, we can calculate the work done by air resistance as follows:

Work Done by Air Resistance = Force of Air Resistance * Distance

To find the force of air resistance, we need to find the deceleration of the projectile due to air resistance. We can use the following equation:

Deceleration = (Final Velocity - Initial Velocity) / Time

Since we do not have the time of flight, we cannot calculate the deceleration accurately. However, we can assume that the deceleration is constant throughout the flight of the projectile.

Using this assumption, we can calculate the average deceleration as follows:

Average Deceleration = (Initial Velocity - Final Velocity) / (2 * Time)

To find the time of flight, we can use the equation of motion for vertical displacement:

Vertical Displacement = Initial Vertical Velocity * Time + 0.5 * g * Time^2

Substituting the given values:

-50 = 0 * Time + 0.5 * 10 * Time^2

Simplifying the equation:

-50 = 5 * Time^2

Time^2 = -10

This equation has no real solutions, which means that the given information is inconsistent. Therefore, we cannot accurately calculate the work done by air resistance.

In conclusion, we cannot determine the exact work done by air resistance without additional information.