| Exam Board | OCR |
|---|---|
| Module | M4 (Mechanics 4) |
| Year | 2003 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Moments of inertia |
| Type | Composite body MI calculation |
| Difficulty | Standard +0.8 This is a composite body MOI problem requiring decomposition of an irregular lamina into rectangles, application of parallel axis theorem, and perpendicular axis theorem. While the techniques are standard for M4, the multi-step calculation with careful bookkeeping of multiple components and two parts makes it moderately challenging, above average difficulty. |
| Spec | 6.04d Integration: for centre of mass of laminas/solids |
2\\
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The diagram shows a uniform lamina $A B C D E F$ in which all the corners are right angles. The mass of the lamina is $3 m$.\\
(i) Show that the moment of inertia of the lamina about $A B$ is $3 m a ^ { 2 }$.\\
(ii) Find the moment of inertia of the lamina about an axis perpendicular to the lamina and passing through $A$.
\hfill \mbox{\textit{OCR M4 2003 Q2 [5]}}