77. A ball rolls down a curved ramp, as shown in the following diagram. Which dotted line best represents the path of the ball after leaving the ramp? 78. Above a flat horizontal plane, arrow A is shot horizontally from a bow at a speed of 20 meters per second, as shown in the following diagram. A second arrow B is dropped from the same height and at the same instant as A is fired. B A. Horizontal plane Compare the amount of time A takes to strike the plane to the amount of time B takes to strike the plane. [Neglect friction.) 79. A rock is thrown horizontally from the top of a cliff at 12 meters per second. Calculate the time required for the rock to fall 45 meters vertically. 80. A ball is thrown horizontally at a speed of 24 meters per second from the top of a cliff. if the ball hits the ground 4,0 seconds later, approximately how high is the cliff? (1) 6.0 m (2) 39 m (3) 78 m (4) 96 m