You decide to test the accuracy of your car\'s speedometer You get on the expres
ID: 1422630 • Letter: Y
Question
You decide to test the accuracy of your car's speedometer You get on the expressway and set your cruise control to 60 miles per hour When you pass the 106 mile marker, your watch says it Is 10:00 00 AM During your drive, you monitor the speedometer carefully it always says that you are driving at 60 miles per hour. When you pass the 116 mile marker, your watch says that it is 10 10:30 AM. Assuming that the mile markers are correctly spaced and your watch is accurate what is your speedometer's % error, to the nearest 1%?Explanation / Answer
in 10 min 30 sec, distance traveled =116-106 = 10 mile
time = (10/60) hr + (30/3600)hr = 0.175 hr
speed = distane / time = 10 / 0.175 = 57.14 mph
error = |(actual speed - shown speed)| / actual speed x 100
= |57.14 - 60 | x 100 / 57.14
= 5 %