In an experiment to measure the Young modulus of glass, a student draws out a glass rod to form a fibre 0.800 m in length. Using a travelling microscope, she estimates its diameter to be 0.40 mm. Unfortunately, it proves impossible to obtain a series of readings for load and extension. The fibre snaps when a load of 1.00 N is hung on the end. The student judges that the fibre extended by no more than 1 mm before it snapped.
Use these values to obtain an estimate for the Young modulus of the glass used. Explain how the actual or accepted value for the Young modulus might differ from this estimate.