| Exam Board | Edexcel |
|---|---|
| Module | M3 (Mechanics 3) |
| Year | 2001 |
| Session | June |
| Marks | 10 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Hooke's law and elastic energy |
| Type | Elastic string with compression (spring) |
| Difficulty | Standard +0.3 This is a straightforward M3 question applying standard energy conservation and equilibrium with friction. Part (a) is direct substitution into elastic PE formula and KE, while part (b) requires balancing spring force with friction—both are routine applications of well-practiced techniques with no novel problem-solving required. |
| Spec | 3.03t Coefficient of friction: F <= mu*R model6.02g Hooke's law: T = k*x or T = lambda*x/l6.02i Conservation of energy: mechanical energy principle |
\includegraphics{figure_2}
A light horizontal spring, of natural length 0.25 m and modulus of elasticity 52 N, is fastened at one end to a point $A$. The other end of the spring is fastened to a small wooden block $B$ of mass 1.5 kg which is on a horizontal table, as shown in Fig. 2. The block is modelled as a particle.
The table is initially assumed to be smooth. The block is released from rest when it is a distance 0.3 m from $A$. By using the principle of the conservation of energy,
\begin{enumerate}[label=(\alph*)]
\item find, to 3 significant figures, the speed of $B$ when it is a distance 0.25 m from $A$. [5]
\end{enumerate}
It is now assumed that the table is rough and the coefficient of friction between $B$ and the table is 0.6.
\begin{enumerate}[label=(\alph*)]\setcounter{enumi}{1}
\item Find, to 3 significant figures, the minimum distance from $A$ at which $B$ can rest in equilibrium. [5]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M3 2001 Q3 [10]}}