"A car travels a certain distance along a straight road and on the way must stop at traffic lights and obey local speed limits. The figure (not pictured but info filled in below) shows the distance the car travels as a function of time. Choose all the correct answers which apply to the speed of the car.
A. The speed at 2.1min (distance = 0.35miles) is less than at 2.4min (distance = 0.55miles)
B. At 2.3min (distance = 0.5miles) the speed is as high as it gets.
C. The speed at 6.0min (distance = 1.30miles) is less than at 2.3min (dist = 0.5miles)
D. The speed is zero at 0.5min (dist = 0miles straight line on graph) and at 3.7min (distance =1.05miles but straight line on graph)
E. The speed does not change from 3min (dist. = 0.95miles) to 3.7min (dist = 1.05miles)
Am I incorrect in my approach with the s=d/t equation? Should my approach be simply taking the magnitude of the velocity vector? Along that line, I am confused regarding "Speed" "Velocity" and "Acceleration" in their relations and definitions and how to apply this to the above and other problems.
The Attempt at a Solution
I have assumed speed s=d/t and have converted the units, although I don't think that is necessary, and I assumed the following were correct at multiple tries (A, AC, AD, ADE) and none of these answers have been correct.
Here is a link to the above mentioned graph. I couldn't figure the photobucket method. Apologies, but I appreciate the help!
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