2. Work
❖ The transfer of energy that occurs when a force applied over a
distance
➢ Ex: Pushing a desk across the room = Work
➢ Ex: Pushing the desk and it won’t move = NO work
■ An object must move as a result of some force for work
to be done
❖ Work = Force (N) x Distance (m)
❖ Work is measured in Joules (J) =Nxm
3. Power
➢ The rate at which work gets done
➢ Measured in Watts (w)
➢ Power = Work (J)/Time (sec)
➢ The more power you supply the faster the works gets done
○ Hmmm… sound familiar with your school work?!?
➢ So the whole Horsepower thing….. Yeah, it’s a real thing
○ 1 Horse can move 750N, 1 meter in 1 second
○ 735.5Nm/sec = 735.5J/sec = 1 Horsepower
4. Machines
They are used to make work easier *Inertia pulled it down
Equals less effort and in less time *Momentum pulled it forward
6. Lever
➢ There is Resistance (load), Effort AND a Fulcrum (pivot point)
➢ Three classes of Levers
○ What is in the middle matters!!!! Just like an OREO or ice
cream sandwich!
7. 3 Classes of Levers
1. First Class Lever: Fulcrum is in the middle
2. Second Class Lever: Resistance is in the middle
3. Third Class Lever: Effort is in the middle
10. Several Types of Pulleys
Single Fixed: Change direction
Single Moving: requires less force
Compound Pulley: changes direction AND requires
less force
11. Mechanical Advantage of Pulleys
The rope being pulled down doesn’t count towards the mechanical
advantage
12. Wheel and Axle
A series of levers connected by a circle
Used to multiple force, speed or distance
