What is the average speed
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What is the average speed

[From: ] [author: ] [Date: 11-09-30] [Hit: ]
avg speed = 20mi/0.53hr = 37.......
A car drives for 20 miles total. The first 10 miles were at 30mph and the next 10 miles were at 50 mph. What is the average speed? Thank you.

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avg speed = total distance/total time

we know the total dist is 20 miles

we need to find the time:

in the first segment, time = dist/speed = 10 miles/30mi/hr = 1/3 hr = 20 mins

in the second segment, time = 10mi/50mi/hr = 1/5 hr = 12 mins

the total time is 32 mins or 0.53hr

therefore, avg speed = 20mi/0.53hr = 37.7 mi/hr

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The average speed is 45mph
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