To find Larry's average speed during the specified time intervals, we will use the formula for average speed, which is:
\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]
Average Speed from Hour 2 to Hour 4
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Calculating the Total Distance from Hour 2 to Hour 4:
- Distance at Hour 4 = 27.5 miles
- Distance at Hour 2 = 13.5 miles
- Distance covered from Hour 2 to Hour 4: \[ \text{Distance} = 27.5 - 13.5 = 14 \text{ miles} \]
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Calculating the Total Time from Hour 2 to Hour 4:
- Time from Hour 2 to Hour 4 = 4 - 2 = 2 hours
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Calculating Average Speed: \[ \text{Average Speed} = \frac{14 \text{ miles}}{2 \text{ hours}} = 7 \text{ miles per hour} \]
Average Speed from Hour 4 to Hour 7
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Calculating the Total Distance from Hour 4 to Hour 7:
- Distance at Hour 7 = 48.5 miles
- Distance at Hour 4 = 27.5 miles
- Distance covered from Hour 4 to Hour 7: \[ \text{Distance} = 48.5 - 27.5 = 21 \text{ miles} \]
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Calculating the Total Time from Hour 4 to Hour 7:
- Time from Hour 4 to Hour 7 = 7 - 4 = 3 hours
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Calculating Average Speed: \[ \text{Average Speed} = \frac{21 \text{ miles}}{3 \text{ hours}} = 7 \text{ miles per hour} \]
Conclusion
- Average Speed from Hour 2 to Hour 4: 7 miles per hour
- Average Speed from Hour 4 to Hour 7: 7 miles per hour
Since Larry's average speed remains the same (7 miles per hour) between both intervals, he stayed the same in terms of speed.