p5 - energy

Question 1

measure mass

Answer 1

using a digital balance

Question 2

measure the energy transferred

Answer 2

if you heat a material using an immersion hater, you can work out energy transferred to the material by measuring:
- potential difference across the immersion heater
- the current through the immersion heater
- the time for which the heater is on
- then calculate energy transferred using this equation : energy transferred (J) = potential difference (V) x current (A) x time (s)

or

use a joulemeter connected between the immersion heater and power supply to measure energy transferred directly

need to insulate material to reduce the transfer of energy from hot material to surroundings

Question 3

measure temp difference

Answer 3

using a thermometer or temperature probe
measure temp before you turn on the immersion heater, and then the temperature at the end of the heating period.
to find temp different, subtract the starting temp from the final temp

Question 4

measuring s.h.c

Answer 4

1) use a digital balance to measure the mass of the object
2) use a voltmeter, ammeter, and stopwatch to measure the energy transferred
3) use a thermometer to measure the temp rise, by reading the scale at eye level
4) repeat your readings, and take an average, ignoring outliers
5) calculate s.h.c using the equation s.h.c (J/Kg K) = change in thermal energy (J) / mass (kg) x change in temp (K)