a) In the point moves in a plane xy; the trajectory of the drawings shows the conventional. The law of motion defined by equations point x = f1 (t), y = f2 (t), where x and y are expressed in cm, t-seconds. Find the equation of the trajectory of the point; at time t1 = 1c determine the velocity and acceleration of the point, and its tangential and normal acceleration and a radius of curvature at the corresponding point of the trajectory. b) A point moves along an arc of radius R = 2m circumference legally S = f (t), S- meters, t - in seconds. Determine the velocity and acceleration at time point t1 = 1c.