Mechanical Comp Question

What is a lever?

A rigid bar that pivots around a fulcrum

What is a fulcrum?

The fixed point a lever turns around

What is the main benefit of a longer lever?

More torque with the same applied force

What is a first-class lever?

Fulcrum between effort and load

Example: seesaw

What is a second-class lever?

Load between fulcrum and effort

Example: wheelbarrow

What is a third-class lever?

Effort between fulcrum and load

Example: tweezers

What is mechanical advantage?

How much a machine multiplies force

What is a pulley?

A grooved wheel with a rope or cable

What does a fixed pulley do?

Changes force direction; ideally gives no force advantage

What does a movable pulley do?

Reduces the effort force needed to lift a load

What happens as supporting rope sections increase?

Required lifting force decreases; rope travel increases

What is a wheel and axle?

A large wheel connected to a smaller axle

What is a wedge?

A moving inclined plane used to split or cut

What is an inclined plane?

A sloped surface that reduces lifting effort

What is a screw?

An inclined plane wrapped around a cylinder

What is torque?

A turning effect of force around a pivot

How can you increase torque?

Increase force or increase distance from the pivot

What is friction?

A force that opposes motion between surfaces

What increases friction?

Often greater normal force or rougher surfaces

What is gravity?

The force that attracts masses toward one another

What is inertia?

Resistance to changes in motion

What is Newton's First Law?

Motion stays unchanged unless a net external force acts

What is Newton's Second Law?

Force = mass × acceleration (F = ma)

What is Newton's Third Law?

Every action force has an equal, opposite reaction force

What is acceleration?

The rate at which velocity changes

What happens to acceleration if force increases?

It increases if mass stays constant

What happens to acceleration if mass increases?

It decreases if force stays constant

What is work in physics?

Force applied through a distance in its direction

What is power?

How quickly work is done

What is kinetic energy?

Energy an object has because it is moving

What is potential energy?

Stored energy, such as energy from height

What is a gear?

A toothed wheel that transfers rotary motion

What happens when a small gear drives a larger gear?

The larger gear turns slower with greater torque ideally

What happens when a large gear drives a small gear?

The smaller gear turns faster with less torque ideally

How do two meshed external gears rotate?

In opposite directions

What does an idler gear do?

Changes rotation direction or spacing, not the overall ratio

What does a crankshaft do?

Converts reciprocating piston motion into rotary motion

What is compression?

A force that squeezes or shortens an object

What is tension?

A pulling force that stretches an object

What does a spring do?

Stores elastic energy when stretched or compressed

What is Hooke's law?

Within its elastic range, spring force is proportional to displacement

What is fluid pressure?

Force exerted per unit area by a fluid

What happens to liquid pressure deeper underwater?

It increases with depth

What is Pascal's principle?

Pressure applied to an enclosed fluid transmits throughout it.

How does a hydraulic lift multiply force?

A larger output piston produces greater force from equal pressure.

What is buoyancy?

The upward force a fluid exerts on an object

What is Bernoulli's principle?

In ideal flow, faster fluid generally has lower static pressure

How does heat transfer by conduction work?

Heat moves through direct contact

How does heat transfer by convection work?

Heat moves through the motion of a liquidor gas

How does heat transfer by radiation work?

Energy travels by electromagnetic waves; no medium is required