| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Newton's laws and connected particles |
| Type | Lift with passenger or load |
| Difficulty | Moderate -0.3 This is a standard M1 Newton's laws problem with two connected objects (packing case and lift). Part (a) requires recognizing zero acceleration means forces balance. Part (b) applies F=ma with given acceleration. Both are routine applications of core mechanics principles with straightforward calculations, making it slightly easier than average but still requiring proper method. |
| Spec | 3.03c Newton's second law: F=ma one dimension3.03f Weight: W=mg |
| Answer | Marks | Guidance |
|---|---|---|
| (a) \(T - 260g = 0\) → \(T = 2550\) N; \(R - 60g = 0\) → \(R = 588\) N | M1 A1 A1 | |
| (b) \(T - 260g = 1.2 \times 260\) → \(T = 2548 + 312 = 2860\) N | M1 A1 | |
| \(R - 60g = 1.2 \times 60\) → \(R = 588 + 72 = 660\) N | M1 A1 | |
| (c) Modelled lift and case as particles, cable as light string | B1 B1 | 9 marks |
**(a)** $T - 260g = 0$ → $T = 2550$ N; $R - 60g = 0$ → $R = 588$ N | M1 A1 A1 |
**(b)** $T - 260g = 1.2 \times 260$ → $T = 2548 + 312 = 2860$ N | M1 A1 |
$R - 60g = 1.2 \times 60$ → $R = 588 + 72 = 660$ N | M1 A1 |
**(c)** Modelled lift and case as particles, cable as light string | B1 B1 | 9 marks |A packing-case, of mass $60$ kg, is standing on the floor of a lift. The mass of the lift-cage is $200$ kg. The lift-cage is raised and lowered by means of a cable attached to its roof.
In each of the following cases, find the magnitude of the force exerted by the floor of the lift-cage on the packing-case and the tension in the cable supporting the lift:
\begin{enumerate}[label=(\alph*)]
\item The lift is descending with constant speed. [3 marks]
\item The lift is ascending and accelerating at $1.2 \text{ ms}^{-2}$. [4 marks]
\item State any modelling assumptions you have made. [2 marks]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 Q3 [9]}}