Posted by Anonymous on Wednesday, July 21, 2010 at 11:08pm.
An odometer in a car has a reading of 50 km at the beginning of a trip and a reading of 125 km half an hour later. What is the average speed of the car?
A. 3.75 km/h
B. 62.5 km/h
C. 1250 km/h
D. 250 km/h
The only way to find the average speed is to divide the total distance by the total time. What is the total distance in here? I thought that I would have to add 50 to 125, then divide that by .30 which indicates half and hour, but I am not getting the correct answer. What is that I'm doing wrong?

PHYSICS  drwls, Thursday, July 22, 2010 at 5:35am
0.30 does not indicate a half an hour. 0.50 does. You are NOT converting to minutes.
(12550)/0.5 = 150 km/h average speed.
That is not any of your choices. There should be a "none of the above" option.
150 km/h would exceed the speed limit in most countries.