Work–Energy Theorem
Work–Energy Theorem
The work–energy theorem states that the net work done on a body equals its change in kinetic energy — a direct route from forces to speeds.
The work is W = ½·m·(v_f² − v_i²). where m is the mass and v_i, v_f the initial and final speeds.
Inputs
m := 1000 kg=1000 kg
v_i := 10 m/s=10 m/s
v_f := 25 m/s=25 m/s
Take the change in kinetic energy.
W := 0.5·m·(v_f^2 - v_i^2)=262500 Nm
Results
A positive result means net work was done on the body to speed it up; a negative value (braking) means energy was removed. It bypasses the detailed force history.
Assumptions & limitations
- Net work over the interval.
- Translational motion.
- Rigid body.