Name________________________________________________
9.1 Day 2 Homework
Solve the following by using dimensional analysis. Show work. Round to the nearest hundredth.
____________________1) An airliner travels 45 miles in 5 minutes. What is its speed in miles per hour?
____________________2) A hose fills a hot tub at a rate of 3.2 gallons per minute. How many hours will it take to
fill a 300-gallon hot tub?
____________________3) Competition speed skydivers have reached record speeds of 614 miles per hour. At
this speed, how many feet would you fall every second?
____________________4) There are approximately 3 million births in the US each year. Find the birth rate in
units of births per minute.
____________________5) If your car gets 28 miles per gallon, how much does it cost to drive 250 miles when gas
costs $3.68 per gallon?
____________________6) The median salary for the New York Yankees in 2008 was $1,875,000. Assuming a 160
game season, express the salary in dollars per game.
____________________7) You want to install carpet in a rectangular room that measures 18 feet by 22 feet. If
carpet costs $28.50 per square yard, how much will it cost to carpet the room?
____________________8) A new sidewalk will be 4 feet wide, 200 feet long, and filled to a depth of 6 inches with
concrete. How many cubic yards of concrete are needed?
9-11 Assume that when you take a bath, you fill the tub to the halfway point, and the tub measures 6 feet by
3 feet by 2.5 feet. When you take a shower, the flow rate of the water is 1.75 gallons per minute, and you
typically spend 10 minutes in the shower. There are 7.5 gallons in one cubic foot.
____________________9) How many gallons of water do you use if you take a bath?
____________________10) How many gallons of water do you use if you take a shower?
____________________11) Do you use more water in the tub or in the shower and by how much (in gallons)?
12-15 Gas mileage varies with the driving speed of a car. Your car gets 39mpg when you drive 55mph and it
gets 32mpg when you drive 70mph. You decide to drive from Phoenix to NYC which is a distance of
approximately 2500 miles. Assume gasoline costs $3.70 per gallon.
____________________12) How long will it take you to get to NYC if your average speed is 55mph?
____________________13) How long will it take you to get to NYC if your average speed is 70mph?
____________________14) What is the cost of the trip if your average speed is 55 mph?
____________________15) What is the cost of the trip if your average speed is 70 mph?
____________________16) An air conditioning system can circulate 320 cubic feet of air per minute. How many
cubic inches of air can it circulate per second?