| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2013 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Forces, equilibrium and resultants |
| Type | Lift with occupant problems |
| Difficulty | Moderate -0.3 This is a straightforward application of Newton's second law to vertical motion with constant acceleration. Part (a) requires resolving forces on the lift system (T - mg = ma with negative acceleration), and part (b) applies the same principle to the woman alone (R - mg = ma). Both parts follow standard M1 procedures with no conceptual challenges, though students must correctly handle the negative acceleration. Slightly easier than average due to clear setup and routine method. |
| Spec | 3.03d Newton's second law: 2D vectors3.03f Weight: W=mg |
| Answer | Marks |
|---|---|
| For system: \((\uparrow), T - 950g - 50g = 1000 \times -2\) | M1 A1 |
| \(T = 7800\) N | A1 |
| (3) |
| Answer | Marks |
|---|---|
| For woman: \((\uparrow), R - 50g = 50 \times -2\) | M1 A1 |
| \(R = 390\) N | A1 |
| (3) | |
| [6] |
## Part (a)
For system: $(\uparrow), T - 950g - 50g = 1000 \times -2$ | M1 A1
$T = 7800$ N | A1
| (3)
## Part (b)
For woman: $(\uparrow), R - 50g = 50 \times -2$ | M1 A1
$R = 390$ N | A1
| (3)
| [6]
**Notes for Question 2:**
- (In both parts, use the mass to decide which part of the system is being considered and M marks can only be scored if an equation contains only forces acting on that part of the system)
- M1 is for a complete method for finding $T$ i.e. for an equation in $T$ only, dimensionally correct, with the correct number of terms.
- First A1 for a correct equation.
- Second A1 for 7800 (N).
- M1 is for a complete method for finding $R$ i.e. for an equation in $R$ only, dimensionally correct, with the correct number of terms.
- First A1 for a correct equation.
- Second A1 for 390 (N).
- N.B. Equation for lift only is: $T - 950g - R = 950 \times (-2)$
---A woman travels in a lift. The mass of the woman is 50 kg and the mass of the lift is 950 kg. The lift is being raised vertically by a vertical cable which is attached to the top of the lift. The lift is moving upwards and has constant deceleration of $2 \text{ m s}^{-2}$. By modelling the cable as being light and inextensible, find
\begin{enumerate}[label=(\alph*)]
\item the tension in the cable; [3]
\item the magnitude of the force exerted on the woman by the floor of the lift. [3]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2013 Q2 [6]}}