Imagine dropping a steel ball bearing into a tall cylinder full of motor oil. Viscous drag has a significant effect on the ball bearing's downward velocity, v(t One family of dynamic models for this takes the form () dv dt 9- kv, where g is the acceleration of gravity and k is a constant. The size of k is related to the viscosity of the medium: when k = 0, equation (*) is the familiar friction-free approximation for a falling mass. The exponent p is an interesting topic for dicussion: for this problem we consider p = 1. In this problem, we use SI units, so t is in seconds, u is in metres per second, etc. Use the international standard value g = 9.807 and assume motor oil has viscosity parameter k = 18. (a) Find v(t). (Assume v(0) = 0.) v(t)= == (b) Let y(t) denote the distance the ball bearing has dropped at time t. (This terminology entails y(0) = 0, and y(t) > 0 for t> 0.) Find y(t). y(t) = (c) Using computer assistance as appropriate, find the time required for the ball bearing to drop 1 metre from its release point. y(t) = 1 when t=