Question

Из двух посёлков, расстояние между которыми 2 км, выехали одновременно в одном направлении 2 велосипедиста. Через 30 минут первый велосипедист догнал второго. С какой скоростью мог двигалтся один из велосипедистов, если другой двигался со скоростью 12км/ч?по матем. писать действия и к ним поеснения

Answer 1

 

30мин=0,5ч 

Если принять, что v=12км/ч- скорость первого велосипедиста(который ехал сэади), то

 1) 12*0,5=6 км- проехал первый велосипедист до места встречи

 2) 6-2=4 км- проехал второй велосипедист до места встречи за 30мин

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

 

Если принять, что v=12км/м- скорость второго велосипедиста( ехавшего впереди), то

1) 12*0,5=6км- проехал второй велосипедист до встречи

2) 6+2=8 км- проехал первый до  места встречи 

3) 8/0,5=16км/ч скорость первого, который догонял.

Answer 2

Problem Analysis

We have two cyclists who start simultaneously from two villages that are 2 km apart. After 30 minutes, one cyclist catches up to the other. We need to determine the speed at which one of the cyclists was traveling, given that the other cyclist was traveling at a speed of 12 km/h.

Solution

Let's assume that the speed of the first cyclist is x km/h. Since the second cyclist is traveling at a speed of 12 km/h, we can set up the following equation based on the distance traveled by each cyclist:

Distance traveled by the first cyclist = Distance traveled by the second cyclist + Distance between the villages

We know that the distance traveled by each cyclist is equal to their respective speeds multiplied by the time traveled. The time traveled by both cyclists is 30 minutes, which is equal to 0.5 hours. Substituting these values into the equation, we get:

x * 0.5 = 12 * 0.5 + 2

Simplifying the equation, we have:

0.5x = 6 + 2

0.5x = 8

Now, we can solve for x by multiplying both sides of the equation by 2:

x = 16

Therefore, one of the cyclists was traveling at a speed of 16 km/h.

Explanation

To solve this problem, we used the concept of relative speed. The distance traveled by each cyclist is equal to their respective speeds multiplied by the time traveled. By setting up an equation based on the distances traveled by each cyclist, we were able to solve for the speed of one of the cyclists.

Please let me know if anything is unclear or if you have any further questions!