Question

ПОМОГИТЕ ПОЖАЛУЙСТА Велосепедист выехал из города А в город Б. через 1 час 30 минут когда он уже проехал 12 километров велосипед сломался ровно 45 минут он пытался его починить, после чего решил вернуться. возвращался он пешком 4 километра в час с получасовой остановкой на середине пути . Построить график и найти 1) скорость велосепедиста на первом участке пути 2) время движения от места отдыха на обратном пути до пункта А 3) время потраченное на весь путь туда и обратно включая время ремонта и отдыха

Answer 1

1 cкорость 75 км в час  2  время движения  2 часа 33 мин 3 общее время 3 часа 33 минуты

Answer 2

Problem Analysis

A cyclist starts from city A and travels to city B. After 1 hour and 30 minutes, when the cyclist has already traveled 12 kilometers, the bicycle breaks down. The cyclist spends exactly 45 minutes trying to fix the bicycle and then decides to return to city A on foot, walking at a speed of 4 kilometers per hour with a 30-minute break in the middle of the way. We need to find: 1. The cyclist's speed on the first leg of the journey. 2. The time it takes for the cyclist to return from the resting place to point A. 3. The total time spent on the entire round trip, including repair time and rest time.

Solution

To solve this problem, we can use a graph to represent the distances and times involved. Let's break down the problem into different parts.

1. Speed on the first leg of the journey: - The cyclist travels 12 kilometers in 1 hour and 30 minutes. - We can calculate the speed using the formula: speed = distance / time. - Convert the time to hours: 1 hour and 30 minutes is equal to 1.5 hours. - Calculate the speed: speed = 12 km / 1.5 hours.

2. Time to return from the resting place to point A: - The cyclist walks at a speed of 4 kilometers per hour. - The distance to be covered is 4 kilometers. - We need to account for the 30-minute break in the middle of the way. - Calculate the time: time = distance / speed.

3. Total time spent on the entire round trip: - The time spent on the first leg of the journey is 1 hour and 30 minutes. - The time spent on the repair is 45 minutes. - The time spent on the return journey is calculated in step 2. - Add up all the times to get the total time.

Let's calculate the values step by step.

Calculation

1. Speed on the first leg of the journey: - Speed = 12 km / 1.5 hours = 8 km/h.

2. Time to return from the resting place to point A: - Time = 4 km / 4 km/h = 1 hour.

3. Total time spent on the entire round trip: - Time on the first leg of the journey: 1 hour and 30 minutes = 1.5 hours. - Time spent on repair: 45 minutes = 0.75 hours. - Time to return from the resting place to point A: 1 hour. - Total time = 1.5 hours + 0.75 hours + 1 hour = 3.25 hours.

Graphical Representation

We can represent the distances and times on a graph to visualize the journey.

City A ------------------------ 12 km ------------------------ Bicycle Breakdown ------------------------ Resting Place ------------------------ City A
       <---------------- 1.5 hours ----------------> <---------------- 0.75 hours ----------------> <---------------- 1 hour ---------------->

Summary

Based on the calculations, we have the following results: 1. The cyclist's speed on the first leg of the journey is 8 km/h. 2. The time it takes for the cyclist to return from the resting place to point A is 1 hour. 3. The total time spent on the entire round trip, including repair time and rest time, is 3.25 hours.

Please let me know if I can help you with anything else.