Answer: Choice A) 0.5 m/s
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Explanation:
At 4 seconds, the distance is 8 meters. Note the point (4,8)
At 8 seconds, the distance is 10 meters. The point here is (8,10)
Find the slope of the line through (4,8) and (8,10)
m = (y2-y1)/(x2-x1)
m = (10-8)/(8-4)
m = 2/4
m = 1/2
m = 0.5
The average speed on this interval is 0.5 m/s
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Another way to look at it:
We've gone from 8 meters to 10 meters, so that's a change of y = 2 meters.
During this, the time has changed from 4 seconds to 8 seconds, which is a difference of x = 4 seconds.
The velocity is the rate of change of distance over time
velocity = (change in distance)/(change in time) = y/x = 2/4 = 0.5 m/s
