Summary of Physics 17 Tension and Weight (1 of 11) What is Tension?

Main Ideas and Concepts

Definition of Tension:
Tension is a force typically associated with strings, cables, or ropes that are under load. It is measured in Newtons, similar to Weight.
Definition of Weight:
Weight is the force exerted by gravity on an object, calculated as the product of the object's mass and the acceleration due to gravity (W = mg). Weight varies depending on the gravitational field strength, such as on the Moon versus Earth.
Free Body Diagrams:
Free Body Diagrams help visualize the forces acting on an object. They illustrate how Weight (downward force) and Tension (upward force) can balance each other out, resulting in no net force and thus no acceleration.
Newton's Third Law:
For every action, there is an equal and opposite reaction. This principle is applied to understand the relationship between Tension and Weight in different contexts.
Tension in Different Scenarios:
The direction of Tension can vary based on perspective:
- For a mass hanging from a string, Tension acts upward.
- For a hook supporting a mass, Tension acts downward relative to the hook.
In systems with Pulleys, Tension can act in multiple directions, but its magnitude remains constant if there is no friction.
Equilibrium Conditions:
An object remains stationary when the forces acting on it are balanced (e.g., Tension equals Weight). If friction is involved, it can also play a role in maintaining equilibrium.

Analyzing Forces:
- Draw a Free Body Diagram for the object in question.
- Identify all forces acting on the object, including Weight (mg) and Tension (T).
- Set up equations based on the equilibrium condition (net force = 0).
- If applicable, consider friction and how it interacts with Tension.
Understanding Perspectives:
- Always consider the perspective when analyzing Tension:
- For the mass, Tension is upward.
- For the hook, Tension is downward.
- In a pulley system, analyze how the direction of Tension changes based on the system's configuration.