1. Work
A force that causes displacement of an object does “work” on the object
Work is equal to force* times displacement [scalar] W = F x d [also W = m x a x d]
*If the force is at an angle to the displacement, only the component of force that is parallel (in the same direction as) the displacement W = F x cos(θ) x d

2. Work Diagrams

3. Kinetic Energy
Kinetic energy depends on velocity (speed) and mass [scalar] KE = ½ m x v2

4. Work-Energy Theorem
Work is equal to the change in total mechanical energy W = ∆KE remember ∆KE = (KEf – KEi) W = ∆GPE remember ∆GPE = (GPEf – GPEi) W = ∆SPE remember ∆SPE = (SPEf – SPEi)

5. The Units of Work & Energy
W = F x d N x m “Newton-meters” the “Joule” J kg x m/sec2 x m kg x m2/sec2
KE = ½ m x v2 kg x (m/sec) kg x m2/sec2
GPE = m x g x h kg x m/sec2 x m kg x m2/sec2