Question

Из пункта А в пункт В вышел пешеход со скоростью 5 км/ч. Одновременно с ним из А в В выехал велосипедист со скоростью 10 км/ч. Велосипедист доехал до В, повернул назад и поехал с той же скоростью навстречу пешеходу. Через сколько часов после начала движения они встретятся, если расстояние между А и В 30 км?Ответ будет 4 часа, помогите подобрать решение!!:3

Answer 1

Pewehod ⇒ V1 (5 km/h)
Velosipedist ⇒ V2 (10 km/h)
rasstoyanie mezhdu A i B ⇒ X (30 km)
znachit tak :
esli oni vyshli odnovremenno togda velosipedist za 3 chasa doberetsya do tochki B, a pewehod za eto vremya proidet polovinu puti (15 km) znachit rasstoyanie mezhdu velosipedistom i pewehodom budet toje 15 km.
Teper velosipedist povorachivaetsya i edet na vstrechu pewehodu togda rasstoyannie budet sokrawatsya s oboih storon, a znachit esli za chas velosipedist proedet 10 km, to pewehod proidet 5 km, teper nado budet pribavit eti rasstoyaniya i poluchim 15 km, znachit oni togda i vstretilis , potomu 4to ih razdelyalo imenno 15 km.
znachit 3 chasa + 1 chas = 4 chasa

Answer 2

Problem Analysis

We are given that a pedestrian and a cyclist start simultaneously from point A and travel towards point B. The pedestrian's speed is 5 km/h, and the cyclist's speed is 10 km/h. The cyclist reaches point B, turns back, and travels towards the pedestrian with the same speed. We need to determine how many hours it will take for them to meet if the distance between points A and B is 30 km.

Solution

Let's break down the problem into steps to find the solution:

1. Calculate the time it takes for the cyclist to reach point B. 2. Calculate the time it takes for the cyclist to travel from point B back towards the pedestrian. 3. Add the times from steps 1 and 2 to find the total time it takes for the cyclist and pedestrian to meet.

Step 1: Time for the cyclist to reach point B

To calculate the time it takes for the cyclist to reach point B, we can use the formula:

Time = Distance / Speed

The distance between points A and B is 30 km, and the cyclist's speed is 10 km/h. Plugging these values into the formula, we get:

Time = 30 km / 10 km/h = 3 hours Therefore, it takes the cyclist 3 hours to reach point B.

Step 2: Time for the cyclist to travel from point B back towards the pedestrian

Since the cyclist is traveling towards the pedestrian with the same speed, the time it takes for the cyclist to travel from point B back towards the pedestrian will also be 3 hours.

Step 3: Total time for the cyclist and pedestrian to meet

To find the total time it takes for the cyclist and pedestrian to meet, we need to add the times from steps 1 and 2:

Total Time = Time to reach point B + Time to travel from point B back towards the pedestrian

Total Time = 3 hours + 3 hours = 6 hours

Therefore, it will take 6 hours for the cyclist and pedestrian to meet.

Answer

The cyclist and pedestrian will meet after 6 hours of starting their journey from point A.

Please let me know if you need any further clarification.