Simple Machines and Work Flashcards

Grade 7 · Science · Flashcards

Essential terms for understanding simple machines, mechanical advantage, and the scientific definition of work.

Flashcards

Work: Force applied to an object multiplied by the distance the object moves in the direction of the force; W = F × d; measured in joules.
Force: A push or pull on an object; measured in newtons (N).
Joule (J): The SI unit of work and energy; 1 J = 1 N × 1 m.
Simple machine: A basic device with few or no moving parts that changes the magnitude or direction of a force.
Mechanical advantage: The ratio of output force to input force for a machine (MA = Fout / Fin); greater than 1 means the machine multiplies force.
Lever: A rigid bar that rotates around a fulcrum to move a load when effort is applied.
Fulcrum: The fixed pivot point of a lever.
Inclined plane: A flat, slanted surface (ramp) that allows a smaller force to be used over a longer distance to raise an object.
Wedge: Two inclined planes back-to-back, used to split or separate objects (e.g., axe, knife).
Screw: An inclined plane wrapped helically around a cylinder; converts rotational force into linear force.
Pulley: A wheel with a grooved rim and a rope; used to redirect or multiply force.
Wheel and axle: A large wheel fixed to a smaller axle; rotating the wheel produces a larger force at the axle.
Compound machine: A device made of two or more simple machines working together.