Physical Science - Chapter 13

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Work and Power * %%Work%%: the energy transferred to a system by an external force when it acts on the system to move it * %%Power%%: the rate of doing work
Machines * %%Simple Machines%%: a basic mechanical device that changes the magnitude, direction, or distance traveled of the force used when doing work * %%Inclined Plane%%: simple machine that consists of a plane whose opposite ends are at different heights * %%Mechanical Advantage%%: the amount by which a simple machine multiplies an input force to produce an output force
Mechanical Advantage and Efficiency * %%Ideal Mechanical Advantage%%: the mechanical advantage for an ideal machine (100% efficient) with no friction * %%Actual Mechanical Advantage%%: the mechanical advantage that accounts for all mechanical losses sustained through using a machine * %%Efficiency%%: a comparison of the amount of usable energy remaining after a process with the original amount of energy that went into the process

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Simple Machine: Lever * %%Lever%%: a simple machine that consists of a rigid bar that turns about a pivot point (the fulcrum) * %%Fulcrum%%: the point about which a lever pivots or rotates
How Levers Work * %%Torque%%: a force that tends to cause a rotation about a pivot point
Classifying Levers * %%First-Class Lever%%: a lever in which the fulcrum is between the input and output forces * %%Second-Class Lever%%: a lever in which the output force is between the input force and the fulcrum * %%Third-Class Lever%%: a lever in which the input force is between the output force and the fulcrum

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Simple Machine: Wheel and Axle * %%Wheel and Axle%%: a simple machine consisting of a wheel with a rod running through its axis that acts as the pivot point
%%Gear%%: a simple machine that consists of a wheel with teeth on its perimeter that mesh with similar teeth of other gears to do work
%%Pulley%%: a simple machine that consists of a wheel and axle system with a groove around the perimeter of the wheel in which a rope, cable, or belt moves with the wheel as it rotates
Pulley Systems * Single pulleys * Block and tackle

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Simple Machine: Inclined Plane * %%Inclined Plane%%: a simple machine that consists of a plane whose opposite ends are at different heights