ISO-TECH DM91E 50 Leads 10:00.00 niceday Aim To determine the specific heat capacity of a metal block. Equipment: 1kg metal blocks, immersion heaters, blue power packs, leads, multimeters, stop clocks, thermometers, petroleum jelly Thermometer Metal Block Immersion Heater 12v Method: • Teaching ideas: • Connect immersion heater to 12V power supply with ammeter and voltmeter. Put some petroleum jelly on the bulb of the thermometer to ensure a good measure of temperature. • Measure the starting temperature of the block Turn the heater on and start the stopclock Record the voltage and current. • Turn the heater off once the temperature reaches 40 °C. Record the time the heater was on for. Measure the maximum temperature the block reaches (this may take a minute of 2 after the heater is off). Calculate: Power: P=IV Electrical energy: P=E/t • 'c' Eh = cmAT • Advise pupils to keep a close eye on the thermometer as blocks any hotter than 40 °C become too hot to move to tidy up/take too long to cool in a lesson!