Question 4
In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A uniform ladder AB AB\,AB of mass 25 kg and length 6 m rests with the end A A\,A on rough horizontal ground and the end B B\,B against a smooth vertical wall. The ladder makes an angle of 60° 60°\,60° with the ground.
The coefficient of friction between the ladder and the ground is 0.35.
A man of mass 80 kg climbs the ladder. The man is modelled as a particle.
a.[7]
Find how far up the ladder the man can climb, measured along the ladder from AAA, before the ladder begins to slip.
b.[2]
State, with a reason, how this distance would change if the wall were rough instead of smooth.
3.4 Forces Questions
87 exam-style questions on OCR (MEI) A Level Maths 3.4 Forces, covering 3.4.1 Language relating to forces, 3.4.2 Acceleration due to gravity, 3.4.3 Identify forces and draw force diagrams, 3.4.4 Resultant of concurrent forces, 3.4.5 Equilibrium of a particle, 3.4.6 Resolve a force into components (A-level only), 3.4.7 Equilibrium condition for resultant zero (A-level only), 3.4.8 Forces in equilibrium sum to zero (A-level only), 3.4.9 Equations for a particle in equilibrium (A-level only), 3.4.10 Frictional force and normal contact force (A-level only), 3.4.11 Model friction with F ≤ μR (A-level only), and 3.4.12 Apply Newton's Laws to friction problems (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.