| Exam Board | OCR |
|---|---|
| Module | M1 (Mechanics 1) |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Forces, equilibrium and resultants |
| Type | Particle with string at angle to wall |
| Difficulty | Moderate -0.3 This is a standard M1 mechanics problem involving resolving forces on an object in equilibrium relative to an accelerating reference frame. Part (i) is straightforward application of F=ma horizontally (0.08 × 1.25 = T sin α). Part (ii) requires resolving vertically (T cos α = 0.08g) then combining equations to find T. While it requires multiple steps and careful resolution of forces, it follows a very standard template for M1 string-tension problems with no novel insight needed. |
| Spec | 3.03c Newton's second law: F=ma one dimension3.03d Newton's second law: 2D vectors |
\includegraphics{figure_2}
An object of mass $0.08$ kg is attached to one end of a light inextensible string. The other end of the string is attached to the underside of the roof inside a furniture van. The van is moving horizontally with constant acceleration $1.25$ m s$^{-2}$. The string makes a constant angle $\alpha$ with the downward vertical and the tension in the string is $T$ N (see diagram).
\begin{enumerate}[label=(\roman*)]
\item By applying Newton's second law horizontally to the object, find the value of $T \sin \alpha$. [2]
\item Find the value of $T$. [5]
\end{enumerate}
\hfill \mbox{\textit{OCR M1 Q2 [7]}}