[填空题]
1.In an experiment, a beaker co 9cp(d28y 2iupthbqf. mp,6zxntaiwg:16wruq;b2fq/kklo *fg (yqp, tf 6ning liquid of mass m is heated with a heater of power P. Then the variation of temperature T of the liquid wb w ;g:f/u*g(qp2o6t6,fl wf1y rqkkqith time t is recorded.
The data from the experiment is shown on the graph below.
(1)On the graph, draw the line of best fit for the data.
(2)Explain why it can not be concluded that the relationship between temperature and time is directly proportional.
2.Theory suggests that
$frac{T-T_0}{t}$=K
where$T_0$ is the temperature when t=0 s.
(1)Using the data given, calculate the percentage uncertainty of $(T−T_0$) at time 25s. $T_0$ = %
(2)Use the graph to determine constant k.
(3)Theory also suggests that another expression for k is given by
$k=frac{P}{mc}$, where c is another constant.
Determine the units of constant c, expressing your answer in fundamental SI units.
