Two particles C C\,C and D D\,D have masses 4m and km km\,km respectively, where k<4k < 4k<4. They are connected by a light inextensible string which passes over a smooth, fixed pulley. The string is taut, and its two hanging sections are vertical. The system is released from rest, and in the subsequent motion C C\,C moves downwards with acceleration of magnitude 35g\displaystyle \frac{3}{5}g53g.
Explain why the acceleration of D D\,D also has magnitude 35g\displaystyle \frac{3}{5}g53g.
Find, in terms of m m\,m and ggg, the tension in the string.
Find the value of kkk.
30 exam-style questions on Edexcel AS Level Maths Forces and Motion, covering 10.1 Force Diagrams, 10.2 Forces as Vectors, 10.3 Forces and Acceleration, 10.4 Motion in 2 Dimensions, 10.5 Connected Particles, and 10.6 Pulleys. Each one has a worked solution and a mark scheme showing where the marks go.