1. A mass of 50 kg falls 70m. If all its potential energy is converted to heat and gravitational acceleration = 9.8 m/s2, then the heat gained is   3500 J   490 J   686 J   34300 J   Hint Half-n-half Clue   2. The heat supplied by a bunsen-burner flame on burning 4 m3 of gas which has a calorific value of 25000 J/m3 is   6250.0 kJ   100000kJ   100.0 kJ   6.2 kJ   Half-n-half Clue   3. Which loses the most heat in cooling to 10oC ?   a kettle filled with water at 60oC   a swimming pool filled with water at 30oC   a glass filled with boiling water   Half-n-half Clue   4. _______ have the highest calorific value.   Carbohydrates   Fats   Sugars   Proteins   Vitamins   Half-n-half Clue   5. Different gases have the same rate of expansion for the same rise in temperature.   True   False   6. Given that 1 cal (about 4.2 J) of heat is lost by 1 g of water in cooling by 1oC, how much heat is lost by 2 g of water in cooling from 75oC to 20oC ?   8.4 J   462.0 J   231.0 J   110.0 J   Half-n-half Clue   7. The heat produced on burning 9 kg of fuel oil which has a calorific value of 39800 kJ/kg is   358200 MJ   358.2 MJ   4.4 MJ   4422.2 MJ   Half-n-half Clue