Study Guide and Intervention (continued) - MathnMind

12-4
Dimensional Analysis Dividing rational expressions that involve units of measure can
also be simplified by dimensional analysis.
Example
SKATING A speed skater skated 1000 meters in 1.14 minutes. Find
his speed in meters per minute.
Use the formula for time and distance, rate time distance.
r t d
r 1.14 minutes 1000 meters t 1.14 minutes, d 1000 meters
Exercises
Complete.
NAME ______________________________________________ DATE ____________ PERIOD _____
Study Guide and Intervention (continued)
Dividing Rational Expressions
r 1000 meters 1.14 minutes Divide each side by 1.14 minutes.
1
1000 m 1.14 minutes
Multiply by the reciprocal.
1000 meters
1.14 minutes
Multiply.
877.2 meters/minute Express as a unit rate.
1. 32 yd 3 ft 3 2. 0.48 m 3 cm 3
3. 144 in 3 ft 3 4. 1400 m/min km/min
5. 48 plants/ft 2 plants/yd 2 6. $9/h $ /min
7. 40 m/s m/min 8. $5.04/doz $ /piece
9. Express 90 kilometers per hour in meters per second.
10. Express 55 miles per hour in miles per minute.
11. Express $4.48 per pound in dollars per ounce.
12. FOOD PRICES A 14-ounce box of cereal costs $3.92. If a 16-ounce box of the same cereal
costs the same per ounce, how much does the 16-ounce box cost?
13. BICYCLING The tires on a bicycle are 30 inches in diameter.
a. Find the number of revolutions per mile.
b. How many times per minute do the tires revolve when the bicycle is traveling at
12 miles per hour? Round to the nearest whole number.
3
14. COOKING A certain recipe calls for cup sugar and it makes 36 cookies.
4
1
a. If 8 tablespoons cup, how many tablespoons of sugar is in each cookie?
2
b. Each tablespoon of sugar contains 48 Calories. If each cookie has 160 Calories, what
percent of the calories are from sugar?
© Glencoe/McGraw-Hill 724 Glencoe Algebra 1