SOLUTION: James covers a distance of 8 meters in the first second of a 100 meter race. Then he sprints at a speed of 9 meters per second. How far is James from the finish line 9 seconds afte

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Question 876149: James covers a distance of 8 meters in the first second of a 100 meter race. Then he sprints at a speed of 9 meters per second. How far is James from the finish line 9 seconds after the race has started? My teacher gave me the equation
an=a1+(n-1)d i just dont understand what to plug in.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Here's how I would do it:
+d+=+r%2At+
9 sec after the race started is 8 sec after
he started sprinting
+d+=+9%2A8+
+d+=+72+
So, he has gone +8+%2B+72+=+80+ m
That means he is +100+-+80+=+20+ m
from the finish line
--------------------
Putting into a formula:
Let +d+ = distance from the finish line
after 9 sec
+d+=+100+-+%28+9%2A%28+9-1+%29+%29+-+8+
+d+=+100+-+72+-+8+
+d+=+20+ m
where +%28+9%2A%28+9-1+%29+%29+ = rate x time