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LEVER (PENGUNGKIT)
• A lever is a simple machine made with a bar free to move about a fixed point. The lever consists of parts, load, load arm, fulcrum, effort arm, and effort.
Lever First Class
• Example– Scissors– Pliers– See-saw
Load
distance of effort
fulcrum
distance of load
Second Class
• Example– Wheelbarrow– Bottle can opener– Paper cutter– Nutcracker
Load
distance of effort
fulcrum
effort
distance of load
The relationship between the effort and load and their respective distance from the fulcrum
Load x Load Arm = Effort x Effort arm Mechanical advantage = load/effort
MA = L/E
Three types of pulleys• A Fixed Pulley
Is a pulley that is attached to stationary structure.
• A Movable Pulley
Is pulley that is not attached to a stationary structure
• A Pulley SystemIn a combination of fixed and movable pulley
• Katrol ganda dengan tarikan ke bawah KM = 2,
• dihitung dari jumlah tali dikurang 1
Katrol ganda dengantarikan ke atas, KM = 3(jumlah tali)
INCLINED PLANES (BIDANG MIRING)
• An inclined plane is a simple instrument consist of a sloped flat surface such as wedges, screws, and bolts.
The MA of an inclined plan is equal to the length of the slope (s) divided by the height (h) of the inclined plane
h
sMA
WHEEL (RODA)
• Bicycle rider can set the ratio of the chain wheel (front gear) and freewheel (back gear) to adjust to the road being travelled