Question

Летчик стреляет из самолета из пушки, скорость самолета относительно земли 900 км/ч,скорость снаряда относительно самолета 750 м/с.Опредилить начальную скорость снаряда относительно земли,если выстрел производится в направление полета впротевоположную сторону

Answer 1

900 км/ч = 250 м/с 
Vсз - скорость самолета отн-но земли 
Vснс - скорость снаряда отн-но самолета 
Vснз - скорость снаряда отн-но земли 
Если выстрел производится в направлении полета 
Vснс = Vснз - Vсз 
750 = Vснз - 250 
Vснз = 1000 м/с 
Если в противоположном 
Vснс = Vснз + Vсз 
750 = Vснз + 250 
Vснз = 500 м/с

Answer 2

Problem Analysis

We are given the following information: - The speed of the airplane relative to the ground is 900 km/h. - The speed of the projectile (bullet) relative to the airplane is 750 m/s. - The shot is fired in the opposite direction of the airplane's flight.

We need to determine the initial speed of the projectile relative to the ground.

Solution

To solve this problem, we can use the principle of relative motion. The velocity of the projectile relative to the ground is the vector sum of its velocity relative to the airplane and the velocity of the airplane relative to the ground.

Let's denote: - v_airplane: velocity of the airplane relative to the ground - v_projectile_airplane: velocity of the projectile relative to the airplane - v_projectile_ground: velocity of the projectile relative to the ground (what we need to find)

According to the principle of relative motion, we have: v_projectile_ground = v_projectile_airplane + v_airplane

Given that v_airplane = 900 km/h and v_projectile_airplane = 750 m/s, we need to convert the units to have consistent measurements.

Conversion of Units

We need to convert the velocity of the airplane from km/h to m/s. To do this, we can use the conversion factor: 1 km/h = 1000 m/3600 s.

Converting the velocity of the airplane: v_airplane = 900 km/h * (1000 m/3600 s) = 250 m/s

Now we have all the necessary values to calculate the velocity of the projectile relative to the ground.

Calculation

Using the principle of relative motion: v_projectile_ground = v_projectile_airplane + v_airplane v_projectile_ground = 750 m/s + 250 m/s = 1000 m/s

Therefore, the initial speed of the projectile relative to the ground is 1000 m/s.

Answer

The initial speed of the projectile relative to the ground, when fired in the opposite direction of the airplane's flight, is 1000 m/s.