G1-18
Show the tension in the string exerted by a swinging pendulum.
The spring scale reads the tension in the string as the pendulum swings, about 25 Newtons at the center and 19 Newtons at the ends of the swing with a bob mass of 1.1 kG. In this setup: F (center) = mg + mrw^2 = mg (3 - 2 cos a) F(end) = mg cos a where by conservation of energy m v^2 /2 = m r^2 w^2 /2 = mgr (1 - cos a) m r w^2 = 2mg ( 1 - cos a)