Edexcel M3 — Question 1 7 marks

Exam BoardEdexcel
ModuleM3 (Mechanics 3)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 1
DifficultyStandard +0.3 This is a standard circular motion problem requiring resolution of forces (lift and weight) and application of F=mv²/r. While it involves multiple steps (resolving vertically and horizontally, then finding the angle), the setup is straightforward and follows a well-practiced M3 technique with no conceptual surprises. The 7 marks reflect routine working rather than difficulty.
Spec6.05a Angular velocity: definitions6.05b Circular motion: v=r*omega and a=v^2/r6.05c Horizontal circles: conical pendulum, banked tracks

A bird of mass 0.5 kg, flying around a vertical feeding post at a constant speed of 6 ms\(^{-1}\), banks its wings to move in a horizontal circle of radius 2 m. The aerodynamic lift \(L\) newtons is perpendicular to the bird's wings, as shown. \includegraphics{figure_1} Modelling the bird as a particle, find, to the nearest degree, the angle that its wings make with the vertical. [7 marks]

AnswerMarks
\(L \sin \theta = mv^2/r = 0.5 \times 36 + 2 = 9\)M1 A1 M1 A1
\(L \cos \theta = 0.5g = 4.9\)M1 A1 A1
\(\tan \theta = 9 \div 4.9 = 1.84\)
\(\theta = 61.4° \approx 61°\)M1 A1 A1
Total: 7 marks
$L \sin \theta = mv^2/r = 0.5 \times 36 + 2 = 9$ | M1 A1 M1 A1 | 
$L \cos \theta = 0.5g = 4.9$ | M1 A1 A1 |
$\tan \theta = 9 \div 4.9 = 1.84$ | |
$\theta = 61.4° \approx 61°$ | M1 A1 A1 |
| | **Total: 7 marks** |
A bird of mass 0.5 kg, flying around a vertical feeding post at a constant speed of 6 ms$^{-1}$, banks its wings to move in a horizontal circle of radius 2 m. The aerodynamic lift $L$ newtons is perpendicular to the bird's wings, as shown.

\includegraphics{figure_1}

Modelling the bird as a particle, find, to the nearest degree, the angle that its wings make with the vertical. [7 marks]

\hfill \mbox{\textit{Edexcel M3  Q1 [7]}}