Question

Jason drives uphill from home to school, averaging 20 miles per hour. On the way back, he drives back downhill from school to home at 60 miles an hour. What was the average speed in miles per hour for his round trip?

Answer 1

To calculate the average speed for the round trip, we divide the total distance by the total time. In this case, the average speed is 30 miles per hour.

Step-by-step explanation:

To calculate the average speed for the round trip, we need to find the total distance and total time. The distance from home to school is the same as the distance from school to home, so it is 2 times the one-way distance. The time taken for the round trip is the sum of the time taken to go uphill and the time taken to go downhill.

The average speed is calculated by dividing the total distance by the total time:

Average Speed = Total Distance / Total Time

In this case, the total distance is 2 times the one-way distance, which is 2 × 20 miles = 40 miles. The total time is the time taken to go uphill plus the time taken to go downhill, which is (20 miles / 20 mph) + (20 miles / 60 mph) = 1 hour + 1/3 hour = 4/3 hour.

Substituting the values into the formula, we get:

Average Speed = 40 miles / (4/3 hour) = 30 miles per hour.

Answer 2

Average velocity = 30 miles per hour

Step-by-step explanation:

Given that

Velocity for uphill = 20 miles per hour

Velocity for downhill = 60 miles per hour

We know that

Distance = Velocity x time

Total distance = Average velocity x total time

Lets take distance from home to school is s

Time taken from home to school= s/20 hr

Time taken from school to home= s/60 hr

Total time =s/20+s/60

Total distance = Average velocity x total time

s + s = Average velocity x (s/20+s/60)

So average velocity = 30 miles per hour