5.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{54642aff-2042-494e-ba4a-8332bd47a751-4_380_326_237_705}
\captionsetup{labelformat=empty}
\caption{Fig. 3}
\end{figure}
Figure 3 shows two particles \(A\) and \(B\) of masses \(m\) and \(k m\) respectively, connected by a light inextensible string which passes over a smooth fixed pulley.
When the system is released from rest with both particles 0.5 m above the ground, particle \(A\) moves vertically upwards with acceleration \(\frac { 1 } { 4 } \mathrm {~g} \mathrm {~m} \mathrm {~s} ^ { - 2 }\).
- Write down, with a brief justification, the magnitude and direction of the acceleration of \(B\).
- Find the value of \(k\).
Given that \(A\) does not hit the pulley,
- calculate, correct to 3 significant figures, the speed with which \(B\) hits the ground.
(3 marks)