1. In the animation the girl in the purple dress measures that the time elapsed between the 1st and the 7th time the ball hits the lower plate is 4s and the girl in the red dress measures the speed of the rocket as 2ms-1. If the distance between the plates is 1m calculate. a. The Speed of the ball measured by the girl in the purple dress. b. The distance travelled by the ball as measured by the girl in the red dress.