Add exercises
	modified:   exp9/report/report9.tex
Merge branch 'master' of github.com:HappyEmu/physics-reports
Add diag
	modified:   exp9/data/readings.ods
	new file:   exp9/report/diag/meas_exp.pdf
	new file:   exp9/report/diag/meas_exp_crop.pdf
	modified:   exp9/report/report9.tex
Merge branch 'master' of github.com:HappyEmu/physics-reports