Mathematics 9709 · AS & A Level · Newton's laws of motion
Newton's laws of motion — practice question
Particles $A$ with mass $0.25\,\text{kg}$ and $B$ with mass $0.75\,\text{kg}$ are fixed to the two ends of a light inextensible string that runs over a fixed smooth pulley. The arrangement is kept at rest with the string taut and its straight sections vertical. Each particle is initially at a height of $h\,\text{m}$ above the floor. The system is released from rest, and $0.6\,\text{s}$ later, while both particles are moving, the string snaps. In the later motion, particle $A$ does not reach the pulley.
(i)[4]
Determine the acceleration of $A$ and the distance covered by $A$ before the string breaks.
(ii)[3]
Find the value of $V$ and the value of $T$.
(iii)[3]
Find the distance travelled by $A$ upwards and the distance travelled by $A$ downwards and hence find $h$.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Apply Newton’s second law to both particles and eliminate $T$” …