Because it's measure the speed according to the car distance traveled and not the direction of the car movement.
Step-by-step explanation:
The newer cars have digital speedometers; the display would register as a forward speed while backing; and the odometer a positive distance as well. ... In those cars the odometer could run in reverse, subtracting miles.
There actually are simple... The newer cars have digital speedometers; the display would register as a forward speed while backing; and the odometer a positive distance as well. ... In those cars the odometer could run in reverse, subtracting miles
The distance from the house to the lake is (2.5 hr)*(48 mi/hr) = 120 miles. The rerurn trip would take (120 mi)/(40 mi/hr) = 3 hours. Distance equals rate times time, so the distance to the lake is 2 1/2 hours times 48 miles per hour.
