Question

Из двух посёлков,расстояние между которыми 2км,выехали одновременно в одном направлении два велосипедиста .Через 30 минут первый велосипедист догнал второго.С какой скоростью мог двигаться один из велосипедистов,если другой двигался со скоростью 12км/ч?

Answer 1

 

 

1)12*0,5=6 (км/ч)-расстояние, которое проехал первый велосипедист

2)6-2=4 (км)-проехал второй велосипедист

3)4:0,5=8 (км/ч)-скорость второго велосипедиста.

 

Ответ:8 км/ч

 

Answer 2

І вариант

Велосипедист со скоростью 12км/ч двигается впереди

12*0,5=6(км) - расстояние до встречи проехал велосипедист со скоростью 12км/ч

6+2=8(км) - проехал до встречи велосипедист, едущий вдогонку

8:0,5=16(км/ч) - скорость велосипедиста, ехавшего сзади

 

ІІ вариант

велосипедист со скоростью 12км/ч двигается сзади первого велосипедиста

12*0,5=6(км) - проехал велосип. со скоростью 12км/ч

6-2=4(км) - проехал велосипедист, едущий впереди

4:0,5=8(км/ч) - скорость велосипедиста, ехавшего впереди

Answer 3

Problem Analysis

We have two cyclists who start simultaneously from two villages, and after 30 minutes, one cyclist catches up with the other. We need to determine the speed of one of the cyclists, given that the other cyclist is moving at a speed of 12 km/h.

Solution

Let's assume that the speed of the first cyclist is x km/h. Since the distance between the two villages is 2 km, we can calculate the time it takes for the first cyclist to catch up with the second cyclist.

The time it takes for the first cyclist to catch up with the second cyclist is equal to the time it takes for the second cyclist to cover the distance between them. Since the second cyclist is moving at a speed of 12 km/h, the time it takes for the second cyclist to cover the distance is given by:

Time = Distance / Speed

Substituting the values, we get:

Time = 2 km / 12 km/h

Simplifying, we find:

Time = 1/6 hours

Since the first cyclist catches up with the second cyclist after 30 minutes, which is equal to 1/2 hour, we can set up the following equation:

1/6 hours = 1/2 hours - 30 minutes

Simplifying, we find:

1/6 hours = 1/2 hours - 1/2 hours/2

1/6 hours = 1/2 hours - 1/4 hours

Now, we can solve for the speed of the first cyclist.

Calculation

To find the speed of the first cyclist, we can use the equation:

Speed = Distance / Time

Substituting the values, we get:

Speed = 2 km / (1/6 hours)

Simplifying, we find:

Speed = 12 km/h

Therefore, the speed of the first cyclist is 12 km/h.

Answer

The first cyclist can move at a speed of 12 km/h.

Explanation

The first cyclist catches up with the second cyclist after 30 minutes. Since the second cyclist is moving at a speed of 12 km/h, the first cyclist must also be moving at a speed of 12 km/h in order to catch up with the second cyclist.