| Exam Board | Edexcel |
|---|---|
| Module | M3 (Mechanics 3) |
| Year | 2003 |
| Session | January |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Hooke's law and elastic energy |
| Type | Elastic string equilibrium and statics |
| Difficulty | Standard +0.3 This is a straightforward equilibrium problem requiring application of Hooke's law to two elastic strings in series. Students must recognize that both strings extend to the same total length, apply T = (λx)/l for each string, and use vertical equilibrium (T₁ + T₂ = mg). The calculation is routine with clearly given values and no conceptual subtlety, making it slightly easier than average. |
| Spec | 6.02g Hooke's law: T = k*x or T = lambda*x/l6.02h Elastic PE: 1/2 k x^2 |
1.
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\caption{Figure 1}
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A particle of mass 5 kg is attached to one end of two light elastic strings. The other ends of the strings are attached to a hook on a beam. The particle hangs in equilibrium at a distance 120 cm below the hook with both strings vertical, as shown in Fig. 1. One string has natural length 100 cm and modulus of elasticity 175 N . The other string has natural length 90 cm and modulus of elasticity $\lambda$ newtons.
Find the value of $\lambda$.\\
(5)\\
\hfill \mbox{\textit{Edexcel M3 2003 Q1 [5]}}