1 An athlete has mass \(m \mathrm {~kg}\) .The athlete runs along a horizontal road against a constant resistance force of magnitude 24 N .The total work done by the athlete in increasing his speed from \(5 \mathrm {~ms} ^ { - 1 }\) to \(6 \mathrm {~ms} ^ { - 1 }\) while running a distance of 50 metres is 1541 J . Find the value of \(m\) .
\includegraphics[max width=\textwidth, alt={}, center]{3a6ecf05-127f-4ddf-959e-233f6bae9171-04_464_1116_247_478} Coplanar forces of magnitudes \(16 \mathrm {~N} , 12 \mathrm {~N} , 24 \mathrm {~N}\) and 8 N act at a point in the directions shown in the diagram. Find the magnitude and direction of the single additional force acting at the same point which will produce equilibrium.