3 15 20 Position velocity and acceleration Suppose the position of an object moving horizontally along a line after t seconds is given by the following functions s f t where s is measured in feet with s 0 corresponding to positions right of the origin 1 a Graph the position function b Find and graph the velocity function When is the object stationary moving to the right and moving to the left c Determine the velocity and acceleration of the object at t 1 d Determine the acceleration of the object when its velocity is zero e On what intervals is the speed increasing 15 f t 12 4t 0 t 5 16 f 1 1 4t 3 0 t 5 17 f t 212 9t 12 0 t 3 18 f t 18t 31 0 t 8 19 f t 21 211 601 0 t 6 20 f t 61 3612 54t 0 t 4 21 A dropped stone on Earth The height in feet of a stone dropped from a bridge 64 feet above a river at t 0 seconds is given by s 1 1612 64 Find the velocity of the stone and its speed when it hits the water H I 22 A dropped stone on Mars A stone is dropped off the edge of a 54 ft cliff on Mars where the acceleration due to gravity is about 12 ft s The height in feet of the stone above the ground I seconds after it is dropped is s 1 ity of the stone and its speed when it hits the ground 61 54 Find the veloc 23 Throwing a stone Suppose a stone is thrown vertically upward from the edge of a cliff on Forth