how would the free body diagram of a pendulum bob hanging by a string from a ledge
The free body diagram of a pendulum bob hanging by a string from a ledge would consist of the following forces:
1. Tension force (T): The string exerts an upward tension force on the bob, preventing it from falling down.
2. Gravitational force (mg): The Earth exerts a downward gravitational force on the bob, due to its weight, which acts at the center of mass of the bob.
Since the bob is hanging from a ledge, there are no other forces acting on it horizontally. Thus, the free body diagram would only include the tension force (T) and the gravitational force (mg) as shown:
T
|
_________|
| m |
|________________|
mg
Here, "m" represents the mass of the pendulum bob. The Tension force (T) acts upwards and opposes the gravitational force (mg) acting downwards.