Question

Question 2 2 pts Given: I launch the ping pong ball at 7 m/sec off of a table that is 30 inches tall. If my angle at launch is 30° Find: What angle is the ball traveling at as it hits the floor? Note that this kind of calculation can be useful for design of the target. Give the answer in degrees and measured as a positive angle from the floor. D Question 3 2 pts Given: The system in the previous question. Find: How far did the ball travel horizontally before it hit the ground? Give your answer in meters but just put in the number.

Answer 1

Initial velocity (v_0) = 7 m/sec theta = 30 degree therefore v_0 cos theta = (7) cos 30 = 6.06 m/sec v_0y sin theta (7) sin 30 = 3.5 m/sec 4 = 30 inches = 0.762 m L_R = 0 h - v_oy t + 1/2 g t^2 0.762 = -3.5 t + 4.9 t^2 = > t = 0.889 sec therefore v_y = v_oy - g t = 3.5 - (9.8) (0.889) = 3.5 - 8.7 = -5.2 m/sec v_ox = v_x = 6.06 m/sec direction tan theta = v_y/v_x = -5.2/6.06 = > theta = -40.63 degree = > theta = 40.63 degree Horizontal theta = 319.4 degree with + x - axis Horizontal distance (x) = v_0 cos theta times t = (6.06) (0.889) x = 5.38 = 5.4 m