Question

Ребята!Помогите пожалуйста) Задача по алгебре на скорость, время, расстояние: Мотоциклист ехал из пункта А в пункт В. Первые 20 минут мотоциклист ехал по грунтовой дороге со скоростью 30 км/ч, после чего путь ему перегородила река. Через реку он плыл на пароме со скоростью 3 м/с в течение получаса. Затем, до пункта В ‐ по шоссе, со скоростью 72 км/ч. От реки до пункта В мотоциклист добрался за 10 минут. Найдите среднюю скорость мотоциклиста (временем на смену транспорта пренебречь).

Answer 1

20м=20/60=1/3ч
30*1/3=10км ехал по грунтовке
3 м/с=3*3600 м/ч=10800 м/ч=10800/1000км/ч=10,8 км/ч-скорость парома
10,8*0,5=5,4 км-плыл на пароме
10м=10/60ч=1/6ч
72*1/6=12 км ехал по шоссе
10+5,4+12=27,4- весь путь
1/3+1/2+1/6=2/6+3/6+1/6=6/6=1 час всё время на путь
27,4:1=27,4 км/ч-средняя скорость

Answer 2

Problem Analysis

To find the average speed of the motorcyclist, we need to calculate the total distance traveled and the total time taken. The motorcyclist traveled on a dirt road for 20 minutes at a speed of 30 km/h, then crossed the river on a ferry at a speed of 3 m/s for 30 minutes, and finally traveled on a highway for 10 minutes at a speed of 72 km/h. We can calculate the total distance and total time and then divide the distance by the time to find the average speed.

Calculation

Let's calculate the total distance and total time step by step.

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = Speed * Time

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = Speed * Time

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = Speed * Time

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours - Distance = 72 km/h * (10/60) hours

4. Total distance = Distance on dirt road + Distance on ferry + Distance on highway

5. Total time = Time on dirt road + Time on ferry + Time on highway

6. Average speed = Total distance / Total time

Let's calculate the values step by step.

Calculation Details

1. Distance traveled on the dirt road: - Speed: 30 km/h - Time: 20 minutes = 20/60 hours - Distance = 30 km/h * (20/60) hours

2. Distance traveled on the ferry: - Speed: 3 m/s - Time: 30 minutes = 30/60 hours - Distance = 3 m/s * (30/60) hours

3. Distance traveled on the highway: - Speed: 72 km/h - Time: 10 minutes = 10/60 hours