(i)[3]
Determine the coefficient of friction between $B$ and the table.
(ii)[6]
$Q$ is now taken away so that $P$ and $B$ start moving. Find the acceleration of $P$ and the tension in the $PB$ segment of the string.
Mathematics 9709 · AS & A Level · Newton's laws of motion
Newton's laws of motion — practice question
A light inextensible string has a small block $B$ of mass $0.25\,\text{kg}$ fixed at its midpoint. Particles $P$ and $Q$, with masses $0.2\,\text{kg}$ and $0.3\,\text{kg}$ respectively, are attached to the two ends. The string runs over two smooth pulleys mounted at opposite sides of a rough table, and $B$ is in limiting equilibrium on the table between the pulleys, with particles $P$ and $Q$ and block $B$ all lying in the same vertical plane (see diagram).