Monday

December 22, 2014

December 22, 2014

Posted by **howard** on Sunday, December 30, 2012 at 11:46pm.

1. every weekend, Phil drives from his home to his favorite amusement park, a distance of 60 miles.

a. If he averages 40 mph for the first half of the trip, what must his average speed for the second half of the trip in order for him to average 50 mph for the entire trip?

b. Suppose that on the trip home, Phil decides to stop a 30 minute dinner break. If he averages 45 mph for the first half of this return trip and 60 mph for the second half of this trip, how many more MINUTES will the return trip take compared to the trip going to the park? (be sure to account for his dinner break.)

- Math -
**drwls**, Monday, December 31, 2012 at 1:55am1.a To average Vav = 50 mph for the entire trip, the 60 miles distance (D) must be covered in a total time of

D/Vav = 6/5 = 1.2 hours

The first 30 miles required 30/40 = 0.75 hours. The remaining 30 miles must be completed in 1.2 -0.75 = 0.45 hours.

The average speed for the second half of the trip must be 30/0.45 = 66.7 mph

1.b The trip home is also 60 miles in length. Total travel time with dinner break = 30/45 + 30/60 hrs + 0.5 h = 1.667 h

Remember that it took him 1.2 hours to get TO the park. With the dinner break and return speeds indicated, it takes 0.467 hours longer to get home.

**Answer this Question**

**Related Questions**

Math - If niti drives her car at 5okm/hr from her home,she reaches the office ...

English - 1. It was great fun last weekend for you to visit our nursing home. 2...

math - A computer store sold a total of 300 items last month. The store sold six...

Math - You plan on going golfing this weekend with a friend. You can either go ...

physical - David's clock ticks once for every two of Phil's clock ticks. How ...

English - Posted by rfvv on Friday, August 29, 2014 at 11:22pm. 1.Thank you for ...

Math - If a voter in the poll is selected at random What is the probability that...

grammar - Is the word Drives transitive or intransitive in the following ...

Math Problems - Phil’s batting average in baseball is 0.625. What is the ...

English - Posted by rfvv on Wednesday, September 3, 2014 at 7:22am. Posted by ...