• is a rod/bar which rests on a fulcrum
• Amount of effort depends on the mass of load, distance between th load & fulcrum & distance between effort & fulcrum
• 3 types; 1st class, 2nd class, 3rd class

1) 1st class - fulcrum is between effort & load (e.g. Claw hammer, Wire cutter, Pryer)

~ effort is smaller

~direction of force is changed

~effort moves longer distance than load

2) 2nd class - load is between fulcrum & effort (e.g. wheel barrow, nutcracker, can-opener)

~ effort is smaller

~same direction

~effort moves a longer distance than load

3) 3rd class - effort is between load & fulcrum (e.g.Ice tongs, Fishing rod, Broom)

~larger effort

~same direction

~effort moves a horter distance than load

Pulley

• a grooved wheel which can move freely around an axle
• change direction of force, effort is smaller

1) Fixed Pulley

~Does not move

~change direction of force, thus makes work wasier & more convenient

~effort needed is more than load to overcome friction

2) Movable Pulley (e.g. Hoisting flags, bringing in boats)

~Does not change direction

~smaller effort used

~Effort move greater distance than load

3) Combined pulley system

~Change direction of force

~Smaller effort is used

~Effort moves a longer distance than load

Wheel & Axle (e.g. Screwdriver, Egg beater, Cross-spanner)

• axle is rigidly connected to larger wheel
• less effort overcome a greater load
• distance moved by effort is more than distance moved by load

Inclined Plane (e.g. Stairs, Ramp, Ladder)

• ramp
• less effort used
• load moves greater distance
• the smaller the angle of inclination, the lesser the effort needed to move load

Gears (e.g. Car, bicycle, Watch)

• wheels w/ teeth
• When 2 gears interlock, they each turn in opposite directions
• When they are connected by wires, they move in the same direction

• is a rod/bar which rests on a fulcrum
• Amount of effort depends on the mass of load, distance between th load & fulcrum & distance between effort & fulcrum
• 3 types; 1st class, 2nd class, 3rd class

1) 1st class - fulcrum is between effort & load (e.g. Claw hammer, Wire cutter, Pryer)

~ effort is smaller

~direction of force is changed

~effort moves longer distance than load

2) 2nd class - load is between fulcrum & effort (e.g. wheel barrow, nutcracker, can-opener)

~ effort is smaller

~same direction

~effort moves a longer distance than load

3) 3rd class - effort is between load & fulcrum (e.g.Ice tongs, Fishing rod, Broom)

~larger effort

~same direction

~effort moves a horter distance than load

Pulley

• a grooved wheel which can move freely around an axle
• change direction of force, effort is smaller

1) Fixed Pulley

~Does not move

~change direction of force, thus makes work wasier & more convenient

~effort needed is more than load to overcome friction

2) Movable Pulley (e.g. Hoisting flags, bringing in boats)

~Does not change direction

~smaller effort used

~Effort move greater distance than load

3) Combined pulley system

~Change direction of force

~Smaller effort is used

~Effort moves a longer distance than load

Wheel & Axle (e.g. Screwdriver, Egg beater, Cross-spanner)

• axle is rigidly connected to larger wheel
• less effort overcome a greater load
• distance moved by effort is more than distance moved by load

Inclined Plane (e.g. Stairs, Ramp, Ladder)

• ramp
• less effort used
• load moves greater distance
• the smaller the angle of inclination, the lesser the effort needed to move load

Gears (e.g. Car, bicycle, Watch)

• wheels w/ teeth
• When 2 gears interlock, they each turn in opposite directions
• When they are connected by wires, they move in the same direction