Question

Теннисист бьёт по мячу и через 0,4 сек тот возвращается к нему после удара о стенку.Локатор посылает сигнал и через 0,0005 сек получает сигнал, отражённый от самолёта. От игрока до стенки 6 м , от локатора до самалёта 75 км.Во сколько раз средняя скорость мяча меньше скорости сигнала локатора?

Answer 1

Скорость мяча v = 2l/t = 2*6/0.4 = 30 м в сек
Скорость сигнала = c = 2L/T = 150000/0.0005 = 300000000 м в сек (можно было и не считать, это скорость света)
v/c = 3e01/3e08 = 1e-07 то есть в 10 000 000 раз меньше.

Answer 2

Problem Analysis

We are given the following information: - The tennis player hits the ball and it returns to him after 0.4 seconds. - The locator sends a signal and receives the signal reflected from the airplane after 0.0005 seconds. - The distance from the player to the wall is 6 meters. - The distance from the locator to the airplane is 75 kilometers.

We need to determine the ratio of the average speed of the ball to the speed of the locator's signal.

Solution

To find the ratio of the average speed of the ball to the speed of the locator's signal, we need to calculate the speeds of the ball and the signal.

Let's start by calculating the speed of the ball.

The time taken by the ball to travel from the player to the wall and back is 0.4 seconds. Since the distance from the player to the wall is 6 meters, the total distance covered by the ball is 2 times the distance to the wall.

Let's calculate the speed of the ball: Speed of the ball = Total distance covered by the ball / Time taken by the ball

The total distance covered by the ball is 2 times the distance to the wall, which is 2 * 6 = 12 meters.

Now we can calculate the speed of the ball: Speed of the ball = 12 meters / 0.4 seconds

Next, let's calculate the speed of the locator's signal.

The time taken by the signal to travel from the locator to the airplane and back is 0.0005 seconds. Since the distance from the locator to the airplane is 75 kilometers, the total distance covered by the signal is 2 times the distance to the airplane.

Let's calculate the speed of the signal: Speed of the signal = Total distance covered by the signal / Time taken by the signal

The total distance covered by the signal is 2 times the distance to the airplane, which is 2 * 75 kilometers.

Now we can calculate the speed of the signal: Speed of the signal = 2 * 75 kilometers / 0.0005 seconds

Finally, let's calculate the ratio of the average speed of the ball to the speed of the locator's signal: Ratio = Speed of the ball / Speed of the signal

Let's calculate the values:

Calculation

- Total distance covered by the ball = 2 * 6 meters = 12 meters - Time taken by the ball = 0.4 seconds - Speed of the ball = 12 meters / 0.4 seconds

- Total distance covered by the signal = 2 * 75 kilometers = 150 kilometers - Time taken by the signal = 0.0005 seconds - Speed of the signal = 150 kilometers / 0.0005 seconds

- Ratio = Speed of the ball / Speed of the signal

Answer

The ratio of the average speed of the ball to the speed of the locator's signal can be calculated using the values above.