3
\includegraphics[max width=\textwidth, alt={}, center]{123017e8-8536-4716-aa01-5e9367770575-04_348_828_251_621}
\includegraphics[max width=\textwidth, alt={}, center]{123017e8-8536-4716-aa01-5e9367770575-04_2717_35_110_2012}
The diagram shows two identical smooth uniform spheres \(A\) and \(B\) of equal radii and each of mass \(m\). The two spheres are moving on a smooth horizontal surface when they collide with speeds \(2 u\) and \(3 u\) respectively. Immediately before the collision, \(A\) 's direction of motion makes an angle \(\theta\) with the line of centres and \(B\) 's direction of motion is perpendicular to that of \(A\). After the collision, \(B\) moves perpendicular to the line of centres. The coefficient of restitution between the spheres is \(\frac { 1 } { 3 }\).
- Find the value of \(\tan \theta\).
\includegraphics[max width=\textwidth, alt={}, center]{123017e8-8536-4716-aa01-5e9367770575-05_2723_33_99_21} - Find the total loss of kinetic energy as a result of the collision.
- Find, in degrees, the angle through which the direction of motion of \(A\) is deflected as a result of the collision.
\includegraphics[max width=\textwidth, alt={}, center]{123017e8-8536-4716-aa01-5e9367770575-06_776_785_255_680}
The end \(A\) of a uniform rod \(A B\) of length \(6 a\) and weight \(W\) is in contact with a rough vertical wall. One end of a light inextensible string of length \(3 a\) is attached to the midpoint \(C\) of the rod. The other end of the string is attached to a point \(D\) on the wall, vertically above \(A\). The rod is in equilibrium when the angle between the rod and the wall is \(\theta\), where \(\tan \theta = \frac { 3 } { 2 }\). A particle of weight \(W\) is attached to the point \(E\) on the rod, where the distance \(A E\) is equal to \(k a ( 3 < k < 6 )\) (see diagram). The rod and the string are in a vertical plane perpendicular to the wall. The coefficient of friction between the rod and the wall is \(\frac { 1 } { 3 }\). The rod is about to slip down the wall. - Find the value of \(k\).
- Find, in terms of \(W\), the magnitude of the frictional force between the rod and the wall.