1. E = m Lf
E = m c θ
E = m Lv

2. E = m c θ
E = m c θ
E = m Lf
E = m c θ

3. Energy = m x Lf Energy = 10 x 340 Energy = 3,400 J Energy = m x Lf
1.a
Energy = x
Energy = 3,400 J
Energy = m x Lf
1.b
Energy = x
Energy = 6,800 J

4. Energy = m x Lf Energy = 10 x 340 Energy = 3,400 J Energy = m x Lf
1.a
Energy = x
Energy = 3,400 J
Energy = m x Lf
1.b
Energy = x
Energy = 6,800 J

5. Energy to melt ice = m x Lf
2.a
= x
= J
Energy to warm up water = m x c x θ
= x x
= J
Total energy required = J J = J

6. Energy to melt ice = m x Lf
2.a
= x
= J
Energy to warm up water = m x c x θ
= x x
= J
Total energy required = J J = J

7. Energy to cool water = m x c x θ
2.b
= x x
= ,800 J
Energy change each minute = ,800 J / 10 min
= ,680 J / Min

8. Energy to cool water = m x c x θ
2.b
= x x
= ,800 J
Energy change each minute = ,800 J / 10 min
= ,680 J / Min

9. Energy to melt ice = m x Lf3.
= x
= ,000 J
Energy transferred = power x time
= W x t
34,000 J
= seconds
34,000 J
50 W

10. Energy to melt ice = m x Lf3.
= x
= ,000 J
Energy transferred = power x time
= W x t
34,000 J
= seconds
34,000 J
50 W

11. Energy from cooling rivets = m x c x θ
4a.
O C because the block of ice is large and will not all melt!
Energy from cooling rivets = m x c x θ
4.b
= x x
= ,300 J
Energy given to melt ice = m x Lf
4.b
= m x
15,300 J
= m = 45 g
15,300 J
340

12. Energy from cooling rivets = m x c x θ
4a.
O C because the block of ice is large and will not all melt!
Energy from cooling rivets = m x c x θ
4.b
= x x
= ,300 J
Energy given to melt ice = m x Lf
4.b
= m x
15,300 J
= m = 45 g
15,300 J
340

13. Energy to change 4g water to steam = m x Lv = 4 x 2,300 = 9,200 J
5.b
Energy to change 10 g steam to water = m x Lv
Energy to change 10 g steam to water = x
Energy to change 10 g steam to water = ,000 J
Energy given out as water cools to 50 C = m x c x θ
= x x
Total heat given out
= 23,000 J + 2,100 J
= 25,100 J
= 2,100 J

14. Energy to change 4g water to steam = m x Lv = 4 x 2,300 = 9,200 J
5.b
Energy to change 10 g steam to water = m x Lv
Energy to change 10 g steam to water = x
Energy to change 10 g steam to water = ,000 J
Energy given out as water cools to 50 C = m x c x θ
= x x
Total heat given out
= 23,000 J + 2,100 J
= 25,100 J
= 2,100 J

15. Energy transferred = power x time6.
= ,000 W x s
= ,000 J
Energy to change water to steam = m x Lv
360,000 J = m x ,300
360,000 J = m = g
2,300

16. Energy transferred = power x time6.
= ,000 W x s
= ,000 J
Energy to change water to steam = m x Lv
360,000 J = m x ,300
360,000 J = m = g
2,300

17. Energy from cooling metal = m x c x θ
Energy from cooling metal = x x
Energy from cooling metal = ,000 J
Energy given to vaporize liquid = m x Lf
50, = x Lf
50, = Lf = 2,500 J/g 20

18. Energy from cooling metal = m x c x θ
Energy from cooling metal = x x
Energy from cooling metal = ,000 J
Energy given to vaporize liquid = m x Lf
50, = x Lf
50, = Lf = 2,500 J/g 20