Temperature, heat and thermal energyIB MYP Physics: Mind map

Exam questions on Temperature, heat and thermal energy

1. A student places a metal spoon heated to 90 °C into a beaker of cold water at 20 °C and records the temperature of the water every minute until the readings stop changing.
   Explain, in terms of particles, why thermal energy is transferred from the spoon to the water.2 marks
2. A swimming pool at 28 °C holds about 500 000 litres of water. A cup of tea at 80 °C holds about 0.25 litres of water.
   The tea is poured into the pool. Explain why energy flows from the tea to the pool even though the pool has more thermal energy.2 marks
3. A student investigates how the length of an aluminium rod changes when it is heated. The rod is 1000 mm long at 20 °C. The increase in length was 0.9 mm for a 40 °C rise in temperature, 1.8 mm for an 80 °C rise, 2.8 mm for a 120 °C rise and 3.7 mm for a 160 °C rise.
   State a testable hypothesis for this investigation, giving a scientific reason, and name one variable that must be controlled.3 marks