#### Free fall 2.0

An object falls freely of a height h=315 meters. How long does it fall during the last 140 meters of its fall?#### Train and bridge

How long, is a train of length L1=450m going to travel a bridge of length L2=150 m? The speed of the train is 72 km/h.#### Line of automobiles

A line of automobiles of length L=0,7 km moves with a speed of V1=54 km/h. The first motorcycle of the line decides to go to join the tail of the column then, returns immediately at the head of the line. Knowing that during this round trip, the speed of the motorcycle V2=20 m/s remained constant. How long, the motorcycle is going to make this round trip?#### Car average speed

During the first part of the distance of the route, a car moves at a speed V1=75 km/h. During the second part of the distance of the route, this car moves at a speed V2=50 km/h. What is the average speed of the car?#### Car average speed 2.0

During the first part of the time of route, a car moves in a speed V1=90 km/h. During the second part of the time of route, this car moves in a speed V2=50 km/h. What is the average speed of the car?#### Free fall

An object in free-fall without initial speed, went through a height h. During the last second of its fall, it went through a height Δh equal to 3/4 of the total height. How long lasted this fall?#### Train acceleration

A motionless train at first, accelerates in a constant way. Near the passenger situated in the "head" of the train, the 1st wagon of the train passed in 10 seconds. How long, passed all the train compound of 16 wagons?#### Free fall 3.0

An object falls freely of a height h=490 meters. What distance is it going to fall during the last 2 seconds of fall?#### Airplane

A plane flies horizontally with a speed V=470 m/s. A man hears the noise of the plane 21 seconds after the passage of the plane above him. From what height flies the plane? Speed of sound: C = 330 m/s.#### Railroad

Two trains of length 300m and 250m are moving. Each train has a speed of 85 km per hour and moving in the opposite direction. How long will it take for them to pass each other?

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Recent problems :

(All problems are in the **Training** section)

- An object falls freely of a height h=315 meters. How long does it fall during the last 140 meters of its fall?
- How long, is a train of length L1=450m going to travel a bridge of length L2=150 m? The speed of the train is 72 km/h.
- A line of automobiles of length L=0,7 km moves with a speed of V1=54 km/h. The first motorcycle of the line decides to go to join the tail of the column then, returns immediately at the head of the line. Knowing that during this round trip, the speed of the motorcycle V2=20 m/s remained constant. How long, the motorcycle is going to make this round trip?
- During the first part of the distance of the route, a car moves at a speed V1=75 km/h. During the second part of the distance of the route, this car moves at a speed V2=50 km/h. What is the average speed of the car?
- During the first part of the time of route, a car moves in a speed V1=90 km/h. During the second part of the time of route, this car moves in a speed V2=50 km/h. What is the average speed of the car?
- An object in free-fall without initial speed, went through a height h. During the last second of its fall, it went through a height Δh equal to 3/4 of the total height. How long lasted this fall?
- A motionless train at first, accelerates in a constant way. Near the passenger situated in the "head" of the train, the 1st wagon of the train passed in 10 seconds. How long, passed all the train compound of 16 wagons?
- An object falls freely of a height h=490 meters. What distance is it going to fall during the last 2 seconds of fall?
- A plane flies horizontally with a speed V=470 m/s. A man hears the noise of the plane 21 seconds after the passage of the plane above him. From what height flies the plane? Speed of sound: C = 330 m/s.
- Two trains of length 300m and 250m are moving. Each train has a speed of 85 km per hour and moving in the opposite direction. How long will it take for them to pass each other?