Question

Турист на мопеді їхав 45 хвилин зі швидкістю 15 км/год, а потім ще 30 хвилин зі швидкістю 40 км/год. Яка середня швидкість туриста на всьому шляху?

Answer 1

Дано:

t1=45хв

t2=30хв

V1=15 км/год

V2= 40 км/год

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Vcep. - ?

Розв'язання:

1) 0,75•15=11,25 (км) - шлях за 45 хвилин при швидкості 15 км/год

2) 0.5•40=20 (км) - шлях за 30 хвилин при швидкості 40 км/год

3) 11,25+20=31,25 (км) - весь шлях

4) 45+30=75 (хв)- увесь час

5) Vc=31,25:1,25=25 (км/год)

Відповідь: 25 км/год

Answer 2

Calculation of Average Speed

To calculate the average speed of the tourist on the entire journey, we need to determine the total distance traveled and the total time taken.

The tourist traveled for 45 minutes at a speed of 15 km/h and then for 30 minutes at a speed of 40 km/h.

Let's calculate the total distance traveled first:

Distance traveled in the first leg of the journey = Speed * Time = 15 km/h * 45 minutes = 11.25 km

Distance traveled in the second leg of the journey = Speed * Time = 40 km/h * 30 minutes = 20 km

Total distance traveled = Distance of the first leg + Distance of the second leg = 11.25 km + 20 km = 31.25 km

Now, let's calculate the total time taken for the entire journey:

Total time taken = Time of the first leg + Time of the second leg = 45 minutes + 30 minutes = 75 minutes

To find the average speed, we divide the total distance traveled by the total time taken:

Average speed = Total distance traveled / Total time taken = 31.25 km / 75 minutes

Calculation:

To convert minutes to hours, we divide the total time taken by 60:

Average speed = 31.25 km / (75 minutes / 60 minutes per hour)

Simplifying the calculation:

Average speed = 31.25 km / (1.25 hours)

Therefore, the average speed of the tourist on the entire journey is:

Average speed = 25 km/h.