# physics

A car starts from rest and reaches a speed of 8.4 m/s in 5.9 seconds. What is its acceleration?

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1. speed / time

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2. well
(change in speed) / time
:)

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Damon
3. well
(change in speed) / (change in time)
:)

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oobleck
4. well...
the "car starts from rest" ... zero speed and time
...hair splitting not needed

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5. there is always a time interval. It just happens that its initial value is zero.

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oobleck
6. V = Vo+a*T
8.4 = 0+a*5.9.
a = 1.42 m/s^2.

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