State how the student can check that the metre rule is vertical.
State and explain which part of the ball the student ought to use as the reference point when measuring $h$.
On Fig. 1.1c, mark and label $h$.
On Fig. 1.1c, draw the position of the student’s eye when measuring $h$.
Suggest two reasons why measuring $h$ accurately is difficult for the student.
For each value of $H$, the mean value of $h$ is $h_{av}$. Complete Fig. 1.2, giving your values of $h_{av}$ to 3 significant figures.
On Fig. 1.3, plot a graph with $h_{av}$/cm on the $y$-axis and $H$/cm on the $x$-axis. Begin the axes at $(0,10)$. Draw the straight line of best fit.
The quantity $e$ is given by $e = \frac{\sqrt{h_{av}}}{\sqrt{H}}$. Theory shows that $e$ is constant. Use two points from the graph to calculate two values of $e$. Comment on whether $e$ is constant for the student’s results.