A mass 7kg of stretches a spring 18cm. The mass is acted on byan external force of 5sin(t/2) N and moves in a medium that impartsa viscous force of 4N when the speed of the mass is 8cm/s. If themass is set in motion from its equilibrium position with an initialvelocity of 4cm/s, determine the position of the mass at any timet. Use 9.8m/s2 as the acceleration due to gravity. Pay closeattention to the units.
u(t) = ? m
