Work Done by Forces
This page introduces the concept of work done by forces in physics. The fundamental formula for calculating work is presented:
W<sub>AB</sub>F = AB × F × cosAB,F
Where:
- W<sub>AB</sub> is the work done
- AB is the displacement
- F is the force
- cosAB,F is the cosine of the angle between the force and displacement vectors
Definition: Work is the product of force, displacement, and the cosine of the angle between them.
The page then explores different scenarios of work:
- Motoring work: When the force is in the same direction as displacement 0°, resulting in positive work.
- Resistive work: When the force opposes the displacement 180°, resulting in negative work.
- Null work: When the force is perpendicular to the displacement 90°, resulting in zero work.
Example: For a weight force P, the work is calculated as W<sub>AB</sub>P = m × g × Z<sub>A</sub>−Z<sub>B</sub>, where Z<sub>A</sub> and Z<sub>B</sub> are the initial and final heights.
The page also introduces the concepts of conservative and non-conservative forces:
Highlight: Conservative forces, like gravity, do not depend on the path taken, while non-conservative forces, like friction, do depend on the path.