In an experiment, a liquid-filled beaker is positioned
y3geubr1 tg7a8,b . pson an electronic balance. An immersion heater with a power rating of P is introduced into the water. Once the water begins to boil, a researcher monitored the change in mass m of the liqui
83 gsbbg1epar7t.y ,u d over time t once the boiling commenced.
The theoretically predicted relationship between time and is =
is the initial mass of the liquid when and is the latent heat of vaporisation of water.
1.Give the units of in fundamental SI units.
2.In a particular experiment, the researcher uses a heater of power 65.0±0.1 W and measures m=0.120±0.001kg, C=0.125±0.001 kg, and t=600±1 s.
(1)Calculate the percentage error in the measured value of .
=
%
(2)For this experiment, calculate the value of and its absolute uncertainty. =
(3)The accepted value of is . Explain why the experimental value does not match the accepted value.
3.The researcher plots a graph to show how m varies with .
(1)Outline why P must be kept constant during the experiment.
(2)Assuming the relationship = is correct, sketch the expected mass-time relationship on the axes below. (There is no need to put numbers to the axes).
(3)Outline how to obtain the value of from the graph you have drawn in c(ii).