The two trains of Party A and Party B run at a constant speed on two parallel tracks. The length of vehicle a is 300m, the speed is 20m / s, the length of vehicle B is 250m, and the speed is 30m / S! The two trains of Party A and Party B run at a constant speed on two parallel tracks. The length of vehicle a is 300m and the speed is 20m / s, and the length of vehicle B is 250m and the speed is 30m / s. calculate: (1) the time of overtaking (2) the time of passing

The two trains of Party A and Party B run at a constant speed on two parallel tracks. The length of vehicle a is 300m, the speed is 20m / s, the length of vehicle B is 250m, and the speed is 30m / S! The two trains of Party A and Party B run at a constant speed on two parallel tracks. The length of vehicle a is 300m and the speed is 20m / s, and the length of vehicle B is 250m and the speed is 30m / s. calculate: (1) the time of overtaking (2) the time of passing

Overtaking time: car B overtakes car a; Because the speed of vehicle B relative to vehicle a is 30-20 = 10m / S;
Therefore, the overtaking time: T = (300 + 250) / 10 = 55s
Passing time: two vehicles face each other, and the relative speed of the two vehicles is 30 + 20 = 50M / S;
Therefore, the passing time: T = (300 + 250) / 50 = 11S

A train is traveling in the rain from north to South at the speed of 18km / h. the passengers sitting at the window see that the rain just falls vertically to the ground. This phenomenon shows that there is a scratch outside the window______ Wind, what's the wind speed______ m/s．

(1) According to 1m / S = 3.6km/h: 18km / h = 5m / S;
(2) Taking the ground as the reference, the train is running from north to South;
     Taking the train as the reference object, the rain falls vertically, and the rain and the train remain relatively stationary;
     Taking the ground as a reference, the rain moves south, so the wind blows south, that is, north wind; The wind speed is the same as the vehicle speed
So the answer is: North; 5．

A train is traveling in the rain from north to South at the speed of 72 km / h. the passengers sitting at the window see that the raindrops just fall vertically to the ground A train is traveling in the rain from north to South at the speed of 18km / h. the passengers sitting at the window see that the raindrops just fall vertically to the ground It's from west to East

Because when the train runs at a uniform speed from north to south, due to the south wind, an air flow will be generated, so that the speed of raindrops is equal to that of freight cars. Taking the train as a reference, raindrops are stationary

A train is traveling in the rain from north to South at the speed of 18km / h. the passengers sitting at the window see that the rain just falls vertically to the ground. This phenomenon shows that there is a scratch outside the window______ Wind, what's the wind speed______ m/s．

(1) According to 1m / S = 3.6km/h: 18km / h = 5m / S; (2) Taking the ground as the reference, the train is running from north to South;      Taking the train as the reference object, the rain falls vertically, and the rain and the train remain relatively stationary;      Taking the ground as a reference, the rain is going south

A train was traveling in the rain from north to south. The passengers sitting at the window saw that the raindrops fell vertically to the ground. This phenomenon shows what the wind is blowing But how can it be clearer

Taking the car as the reference system, the horizontal partial speed of rain should be equal to the speed of the car. The two are relatively stationary. The speed of rain is equal to the speed of the car from north to south, which can be known as the north wind

A train is traveling in the rain from north to South at the speed of 18km / h. the passengers sitting at the window see that the rain just falls vertically to the ground. This phenomenon shows that there is a scratch outside the window______ Wind, what's the wind speed______ m/s．

(1) According to 1m / S = 3.6km/h: 18km / h = 5m / S;
(2) Taking the ground as the reference, the train is running from north to South;
     Taking the train as the reference object, the rain falls vertically, and the rain and the train remain relatively stationary;
     Taking the ground as a reference, the rain moves south, so the wind blows south, that is, north wind; The wind speed is the same as the vehicle speed
So the answer is: North; 5．