FrictionEdexcel International A Level Maths: Flashcards

Exam questions on Friction

1. A box of mass $12$ kg rests on a rough horizontal floor. The coefficient of friction between the box and the floor is $0.35$. A horizontal force of magnitude $P$ N is applied to the box. Take $g=9.8$ m s⁻².
   The force $P$ is now increased to $50$. Find the acceleration of the box.2 marks
2. A block of mass $10$ kg rests on a rough plane inclined at an angle $\alpha$ to the horizontal, where $\tan\alpha=\frac34$. The block is on the point of sliding down the plane. Take $g=9.8$ m s⁻².
   The block is replaced by one of mass $20$ kg of the same material. Without calculating friction forces, state whether the block will slide down the plane, giving a reason.2 marks
3. A particle $P$ of mass $2$ kg is on a rough horizontal floor. The coefficient of friction between $P$ and the floor is $0.4$. The particle is pulled by a light rope inclined at $25^\circ$ above the horizontal. The tension in the rope is $T$ N. Take $g=9.8$ m s⁻².
   Find the least value of $T$ for which the particle is on the point of moving.3 marks