Answer:
-4432.5 m . . . or . . . -4.4325 km
Explanation:
You can use the formula for average velocity, fill in the given values, and solve for displacement.
average velocity = displacement/time
-98.5 m/s = displacement/(45 s)
Multiply by time:
(-98.5 m/s)(45 s) = displacement = -4432.5 m
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Keeping units with the numbers serves as a check on the math. (m/s)·s = m. The units work the same way variables do: they can be multiplied and divided, raised to a power, canceled. If the units of the problem don't work out right, you're probably doing it wrong. (Note, you can only add and subtract numbers that have the same (identical) units--the same rule as for combining like terms.)