For Individual or Group Work A formula that has many uses for drivers is, called the distance formula.
If you are driving a car, then d is the distance you travel (how many miles) r is the rate (how fast you are driving in miles per hour) t is the time (how many hours you drive).
Use the distance formula as you work Exercises 51–54 in order. d = rt
51. Suppose you are driving on Interstate highways at an average rate of 70 miles per hour. Use the distance formula to find out how far you will travel in (a) 2 hours; (b) 5 hours; (c) 8 hours.
A.) d = rt d= 70 mph x 2 hours d= 140 miles
B.) d = rt d=70mph x 5 hours d= 350 miles
C.) d = rt d = 70 mph x 8 hours d = 560 miles
52. If an ice storm slows your driving rate to 35 miles per hour, how far will you travel in (a) 2 hours, (b) 5 hours, (c) 8 hours? Show how to find each answer using the formula. (d) Explain how to find each answer using the results from Exercise 51 instead of the formula.
A.)
35mph x 2 hours = 70 miles
B.)
35mph x 5 hours = 175 miles
C.) d = 35mph x 8 hours = 280 miles
D.) Multiply the hours traveled by the miles traveled per hour.
53. Use the distance formula to find out how many hours you would have to drive to travel the 3000 miles from Boston to San Francisco if your average rate is (a) 60 miles per hour; (b) 50 miles per hour; (c) 20 miles per hour (which was the speed limit 100 years ago).
A.) d = rt
3000 miles divided by 60 mph= 50 hours
B.) d = rt
3000 miles divided by 50 mph = 60 hours
C.) d = rt
3000 miles divided by 20 mph = 150 hours
54. Use the distance formula to find the average driving rate (speed) on each of these trips. (Distances are from World Almanac.) (a) It took 11 hours to drive 671 miles from Atlanta to Chicago. (b) Sam
