| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2003 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Moments |
| Type | Uniform beam on two supports |
| Difficulty | Moderate -0.3 This is a standard M1 moments problem requiring equilibrium conditions (sum of forces = 0, sum of moments = 0) with straightforward algebra. The equal reactions constraint simplifies the problem significantly, making it slightly easier than average for mechanics questions, though it still requires systematic application of two equilibrium principles. |
| Spec | 3.04a Calculate moments: about a point3.04b Equilibrium: zero resultant moment and force |
1.
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A uniform plank $A B$ has mass 40 kg and length 4 m . It is supported in a horizontal position by two smooth pivots, one at the end $A$, the other at the point $C$ of the plank where $A C = 3 \mathrm {~m}$, as shown in Fig. 1. A man of mass 80 kg stands on the plank which remains in equilibrium. The magnitudes of the reactions at the two pivots are each equal to $R$ newtons. By modelling the plank as a rod and the man as a particle, find
\begin{enumerate}[label=(\alph*)]
\item the value of $R$,
\item the distance of the man from $A$.\\
(4)
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2003 Q1 [6]}}