Let's calculate the temperature in both cities after five hours.
City A
- Initial temperature: 70°F
- Rate of change: -5°F per hour
- Time: 5 hours
Temperature change: \[ \text{Temperature change} = \text{Rate of change} \times \text{Time} = -5°F \times 5 \text{ hours} = -25°F \]
Temperature after 5 hours: \[ \text{Final temperature} = \text{Initial temperature} + \text{Temperature change} = 70°F - 25°F = 45°F \]
City B
- Initial temperature: 70°F
- Rate of change: -3°F per hour
- Time: 5 hours
Temperature change: \[ \text{Temperature change} = \text{Rate of change} \times \text{Time} = -3°F \times 5 \text{ hours} = -15°F \]
Temperature after 5 hours: \[ \text{Final temperature} = \text{Initial temperature} + \text{Temperature change} = 70°F - 15°F = 55°F \]
Summary of Temperatures
- City A: 45°F
- City B: 55°F
Conclusion
City B is warmer than City A by: \[ \text{Temperature difference} = 55°F - 45°F = 10°F \]
Final Answer: City B is warmer, and the difference in their temperatures after five hours is 10°F.