Note. Neglect air resistance in problems concerning projectiles. y (m) 11.90 The motion of a particle is defined by the equations x = 2 cos t and y 1-4 cos 2t, where x and y are expressed in metres and t is ex- pressed in seconds. Show that the path of the particle is part of the parabola shown, and determine the velocity and the acceleration when (a) t = 0, (b) t=1.5s Fig. P11.90 y = 5-2x 2 x (m) t = 0