Activity 2 COUPLES AND CENTER OF GRAVITY 1. A ball weighing 20 g rests on two boards arranged as a 45" through with one board vertical. What are the reactions of the board on the ball? 2. Given forces of 10 g upward acting @ 0 ft mark, 20 g upward @ 3 ft mark and 15g downward @ 5 ft mark. Determine the magnitude of the resultant and its point of application 3. Find the center of gravity of the figure shown below 3' 2" 6" 1" 8"