[填空题]
In an experiment, the free-fall of a ball bearing is used to measure the acceleration due to gravity. The ball bearing is suspended with an electromagnet. Then it is released from a height of h above a table.
The time t needed for the ball bearing to reach the ground after release is measured. The experiment is repeated for different values of ℎh. The theoretically predicted relationship between time t and h is.
$t^2=\frac{2h}{g}$
(1)State why there is a need to collect data for a range of values of ℎh to verify this relationship.
(2)The experimental data for $t^2$ and h are plotted on the graph below.
(1)Draw the line of best fit for the plotted data on the graph.
(2)Suggest whether the data is consistent with the theoretical prediction.
(3)By using the line of best fit, determine a value for g and state the units. g = $m\,s^{-2}$
3.The theoretical relationship is for an object falling in a vacuum.
(1)Compare the experimental result to the accepted value of g and suggest a reason for the discrepancy.
(2)State and explain whether the source of error in (c)(i) is a systematic or random error.
