-insertion ulna 8. A 36.5 kg boy walks along a plank that sits atop a fence. The plank is 6.00 m in length and 24.0 kg in mass. od a. What is the normal force on the plank due to the wall when the boy is 0.35 m from the fence? b. How far from the fence can he walk before the plank's right side swings down? 4.33 m - Wall -Fence 9. A uniform beam of length 1.00 m and mass 10.0 kg is attached to a wall by a cable as shown. A small 50.0 kg mass is attached to the beam 30.0 cm from the wall. Calculate the tension in the cable and the horizontal and vertical forces exerted by the wall on the beam. cable 30° 30.0 cm 1.00 m