A child is playing with a toy comprised of a massless 85 cm string attached to a small 0.04 kg ball. The child swings the ball in a horizontal circle so that the period of the ball's rotation is 1.3 second. The string makes an angle of 30 degree to the horizontal as the ball orbits the child's hand. What is the speed and acceleration of the ball? (how to get 3.56 m/s and 17.2 m/s^2 as answer)