Work-energy theorem

Definition

The work-energy theorem states that the net work done on an object is equal to its change in kinetic energy. Mathematically, it is expressed as $W_{net} = \Delta KE$.

5 Must Know Facts For Your Next Test

1. The work-energy theorem connects the concepts of work and kinetic energy through the equation $W_{net} = \Delta KE$.
2. Net work (W_net) is the total work done by all forces acting on an object.
3. Kinetic energy (KE) is given by the formula $KE = \frac{1}{2}mv^2$, where m is mass and v is velocity.
4. If the net work done on an object is positive, the object's kinetic energy increases; if negative, its kinetic energy decreases.
5. The work-energy theorem applies to both constant and variable forces.

Review Questions

• What does the work-energy theorem state about the relationship between net work and kinetic energy?
• How do you calculate kinetic energy for an object with mass m and velocity v?
• If a car's speed doubles, how does its kinetic energy change according to the work-energy theorem?

Related terms

Work:

Work is defined as the product of force and displacement in the direction of force: $W = Fd \cos(\theta)$.

Kinetic Energy:

Kinetic Energy is the energy possessed by an object due to its motion, calculated as $KE = \frac{1}{2}mv^2$.

Net Force: Net Force is the vector sum of all individual forces acting on an object.