Thermodynamics

1. Thermodynamics If there was a thermometer attached to the rubber band, what would you observe?

2. Thermodynamics If there was a thermometer attached to the rubber band, what would you observe? The temperature goes up

3. Thermodynamics If there was a thermometer attached to the rubber band, what would you observe? The temperature goes up ∆Q α ∆T ∆Q is the heat involved

5. Thermodynamics Heat ∆Q α ∆T

6. Thermodynamics Heat ∆Q α ∆T

7. Thermodynamics Heat ∆Q α ∆T or ∆Q = (slope) m ∆T ∆Q m∆T

8. Thermodynamics Heat ∆Q α ∆T or ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Iron m∆T

10. Thermodynamics Heat ∆Q = (slope) m ∆T The slope of this graph is called the specific heat capacity. For water, the specific heat capacity is 4.2 kj/kg-oC

11. Thermodynamics Heat ∆Q = (4.2 kj/kg-oC ) m ∆T How much heat is required to raise the temperature of 10 kg of water by 20 oC?

12. Thermodynamics Heat ∆Q = (4.2 kj/kg-oC ) m ∆T How much heat is required to raise the temperature of 10 kg of water by 20 oC? Heat = (4.2 kj/kg-oC ) (10 kg) (20 oC) = 840 kj

13. Thermodynamics Heat ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Clay, Marble m∆T

15. Thermodynamics Heat ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Clay, Marble m∆T

16. Thermodynamics Heat ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Clay, Marble m∆T

17. Thermodynamics Heat ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Clay, Marble m∆T

18. Thermodynamics Heat ∆Q = (slope) m ∆T ∆Q Water NOTE: Equal masses Clay, Marble m∆T Small change Large change

20. Thermodynamics Heat ∆Q = (slope) m ∆T The variation in temperature between day and night on mars can be as much as 150 degree Fahrenheit, while the variation in temperature on the earth is far smaller. Why?