the specific heat capacity for water is 4200 J/kgoC and lead is 130 J/kgoC.

1. How much heat must be added to 1 cup of water (250 ml or 0.25 kg) at 23C to raise the temperature to 80C? (59850 J)

2. How much heat must be added to 1.5 kg of lead C at 23C to raise the temperature to 180C? (30615 J)

3. What is the final temperature of a 230 ml of water at 22oC when it absorbs 41 000 J of heat energy? (64C)

4. What mass of water can be raised from 20oC to 45oC when it absorbs 19 000 J of heat energy? (0.18 kg)

5. What is the heat capacity of a liquid if 2.6 kg of this liquid is raised from 20 to 35C when it absorbs 90 kJ of heat energy (2308 J/kg*C)

6. Find the efficiency of a 1200 W kettle that heats 1.5 kg of water from 20C to 40C in 3.0 minutes (58%)

7. Find the efficiency of a 200 W kettle that heats 0.40 kg of water from 20C to 50C in 5.0 minutes. (84%)

8. A 1200 W microwave oven raises 0.15 kg of water from 20 to 65C in 90 seconds. What is its efficiency? (26%)

could u explain these questions pls ?