(a(i))[2]
State two ways in which the dimensions of the rubber band change as the mass is added to section XY.
(a(ii))[1]
State the form of energy stored in the stretched rubber band.
(b(i))[2]
State what the principle of moments says.
(b(ii))[1]
Explain why the force exerted by the rubber band on section XY is greater than the weight of the mass.
(b(iii))[2]
The mass hanging from section XY in Fig. 1.2 weighs $4.0\,\text{N}$. Calculate the force that the rubber band exerts on section XY.
(b(iv))[1]
Explain how your answer to (b)(iii) changes if the weight of section XY cannot be ignored.