Physics (AS & A Level) · May / June 2017 · Paper 11 · Question 20

A wire of diameter d and length l hangs vertically from a fixed point. The wire is extended by hanging a mass M on its end. The Young modulus of the wire is E. The acceleration of free fall is g. Which equation is used to determine the extension x of the wire?

1. Ax = \frac{Ml}{\pi d^2 E}
2. Bx = \frac{Mgl}{\pi d^2 E}
3. Cx = \frac{4Mgl}{\pi d E}
4. Dx = \frac{4Mgl}{\pi d^2 E}

As printed in the paper