Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
One end of a light inextensible string is fixed at point $A$. Its other end is fastened to a particle $P$ of mass $m\,\text{kg}$, which hangs vertically beneath $A$. $P$ is also connected to one end of a light elastic string with natural length $0.25\,\text{m}$. The other end of that string is attached to point $B$, which is $0.6\,\text{m}$ from $P$ and lies on the same horizontal level as $P$. A horizontal force of magnitude $7\,\text{N}$ acting on $P$ keeps the system in equilibrium (see Fig. 1).
(i)[2]
Calculate the modulus of elasticity for the elastic string.
(ii)[4]
After the $7\,\text{N}$ force is removed, $P$ is released from rest. In the motion that follows, $P$ first comes to instantaneous rest at a point where $BP = 0.3\,\text{m}$ and the elastic string makes an angle of $30^\circ$ with the horizontal (see Fig. 2). Find the value of $m$.
Worked solution & mark scheme
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