Torque  Mass on Plank with String (8:59)
Example: A 0.300 kg mass rests on a 0.395 m long, 0.764 kg, uniform wooden plank supported by a string as shown in the figure. If the mass is 0.274 m from the wall and the angle between the string and the plank is 32.1°, (a) What is the force of tension in the string? and (b) What is the normal force from the wall?
This is an AP Physics 1 Topic. Content Times: 0:07 The problem 1:17 The free body diagram 3:45 Net torque 5:41 Substituting in numbers 6:53 Net force 8:02 The demonstration 
