| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2005 |
| Session | June |
| Marks | 13 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Forces, equilibrium and resultants |
| Type | Connected particles via tow-bar on horizontal surface |
| Difficulty | Moderate -0.3 This is a standard M1 mechanics question involving Newton's second law applied to connected particles and subsequent motion with deceleration. Parts (a)-(c) require straightforward application of F=ma and kinematic equations with clear problem setup. Part (d) requires understanding of vertical force components but is still routine. Slightly easier than average A-level due to the structured, multi-part nature guiding students through the solution with standard techniques. |
| Spec | 3.02d Constant acceleration: SUVAT formulae3.03a Force: vector nature and diagrams3.03b Newton's first law: equilibrium3.03c Newton's second law: F=ma one dimension3.03d Newton's second law: 2D vectors3.03e Resolve forces: two dimensions3.03k Connected particles: pulleys and equilibrium3.03l Newton's third law: extend to situations requiring force resolution |
| Answer | Marks |
|---|---|
| 7 | 600 |
| Answer | Marks |
|---|---|
| Hence normal reaction is increased | M1 A1 |
Question 7:
7 | 600
300 T T 1500
(a) Lorry + Car: 2500a = 1500 – 300 – 600
a = 0.24 m s–2
(b) Car: T cos 15 – 300 = 900a OR Lorry: 1500 – T cos 15 – 600 = 1600a
Sub and solve: T ≈ 534 N
(c) 300 Deceleration of car = 300/900 = 1/3 m s–1
Hence 62 = 2 x 1/3 x s ⇒ s = 54 m
(d) Vertical component of T now removed
Hence normal reaction is increased | M1 A1
A1
(3)
M1 A1
↓ ↓
M1 A1
(4)
M1 A1
M1 A1
(4)
M1
A1 cso
(2)\includegraphics{figure_4}
Figure 4 shows a lorry of mass 1600 kg towing a car of mass 900 kg along a straight horizontal road. The two vehicles are joined by a light towbar which is at an angle of $15°$ to the road. The lorry and the car experience constant resistances to motion of magnitude 600 N and 300 N respectively. The lorry's engine produces a constant horizontal force on the lorry of magnitude 1500 N. Find
\begin{enumerate}[label=(\alph*)]
\item the acceleration of the lorry and the car, [3]
\item the tension in the towbar. [4]
\end{enumerate}
When the speed of the vehicles is $6 \text{ m s}^{-1}$, the towbar breaks. Assuming that the resistance to the motion of the car remains of constant magnitude 300 N,
\begin{enumerate}[label=(\alph*)]
\setcounter{enumii}{2}
\item find the distance moved by the car from the moment the towbar breaks to the moment when the car comes to rest. [4]
\item State whether, when the towbar breaks, the normal reaction of the road on the car is increased, decreased or remains constant. Give a reason for your answer. [2]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2005 Q7 [13]}}