| Exam Board | Edexcel |
|---|---|
| Module | M3 (Mechanics 3) |
| Year | 2002 |
| Session | January |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Hooke's law and elastic energy |
| Type | Vertical elastic string: released from rest at natural length or above (string initially slack) |
| Difficulty | Standard +0.3 This is a standard M3 elastic string energy problem requiring energy conservation (equating GPE lost to elastic PE gained) to find extension, then applying Hooke's law for acceleration. The setup is straightforward with clear given values, and both parts follow textbook methods with no novel insight required. Slightly above average difficulty due to being M3 content and requiring careful algebraic manipulation of the quadratic equation in part (a). |
| Spec | 6.02h Elastic PE: 1/2 k x^26.02i Conservation of energy: mechanical energy principle |
One end of a light elastic string, of natural length 2 m and modulus of elasticity 19.6 N, is attached to a fixed point $A$. A small ball $B$ of mass 0.5 kg is attached to the other end of the string. The ball is released from rest at $A$ and first comes to instantaneous rest at the point $C$, vertically below $A$.
\begin{enumerate}[label=(\alph*)]
\item Find the distance $AC$. [6]
\item Find the instantaneous acceleration of $B$ at $C$. [3]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M3 2002 Q2 [9]}}