Mathematics 9709 · AS & A Level · Newton's laws of motion
Newton's laws of motion — practice question
Particles $A$ and $B$, with masses $2\text{ kg}$ and $6\text{ kg}$ respectively, are fastened to the two ends of a light inextensible string. The string goes over a smooth fixed pulley, and the particles hang vertically beneath the pulley. At the start, both particles are at rest at a height of $3.2\text{ m}$ above the horizontal ground level (see diagram). Particle $A$ is then projected vertically downwards with speed $1.2\text{ m s}^{-1}$.
(a)[4]
Determine the tension in the string and the size of the acceleration of the particles.
(b)[2]
During the later motion, $A$ never reaches the ground and neither particle gets to the pulley. When $B$ reaches the ground, it does not bounce back. Determine the time that $B$ is in motion.
(c)[4]
Determine the distance between the lowest point and the highest point reached by $A$.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use N2L for particle $A$, particle $B$ or the whole system” …