Question 5
In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A box of mass 12 kg is pulled along a rough horizontal floor by a force of magnitude 20 N acting at an angle of 25° 25°\,25° above the horizontal. The box is modelled as a particle and the coefficient of friction between the box and the floor is 0.1.
a.[5]
Find the acceleration of the box.
b.[2]
The box is now pushed along the same floor by a force of magnitude 20 N acting at an angle of 25° 25°\,25° below the horizontal. Explain why the acceleration of the box will now be less than the acceleration in part (a).
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.