MCAT Physics

vectors

Physical quantitates that have both magnitude and direction. Displacement, velocity, acceleration, and force.

scalars

Quantities without direction. Scalar quantities may be the magnitude of vectors, like speed, or may be dimensionless, like coefficients of friction.

vector addition

Tip-to-tail method, or break the vector into its component parts and use Pythagorean theorem

vector subtraction

Change the direction of the subtracted vector and then do a tip-to-tail addition

vector multiplication

free body diagrams

Representation of the forces acting on an object

translational equilibrium

Occurs in the absence of any net forces acting on the object

rotational equilibrium

Occurs in the absence of any net torques acting on an object. The center of mass is the most commonly used pivot point

displacement

Vector representation of a change in position. path independent

distance

A scalar quantity that reflects the path traveled

velocity

force

Any push or pull that has the potential to result in an acceleration

gravity

The attractive force between 2 objects as a result of their masses

friction

mass

A measure of the inertia of an object - its amount of material

weight

The force experience by a given mass due to the gravitational attraction to the earth

acceleration

The vector representation of the change in velocity over time

torque

1st law newton

Any object will remain at rest or move with a constant velocity if there is no net force on the object.

2nd law newton

F=ma

3rd law newton

An equal reaction warrants the opposite reaction.

linear motion

projectile motion

Contains both an x- and y- component. Only force action on object is gravity. X velocity is constant

inclined planes

Force components:

Parallel to the ramp use sin.

Perpendicular to the ramp use cos

circular motion

structural proteins

kinetic energy

potential energy

Energy stored within a system

gravitational potential energy

elastic potential energy

chemical potential energy

Energy stored in the bonds

conservative forces

Path independent and do not dissipate the mechanical energy of a system. Gravity and electrostatic forces

nonconservative forces

Path dependent and cause dissipation of mechanical energy from a system. Friction, air resistance, and viscous drag

work

power

work-energy theorem

mechanical advantage

The factor by which a simple machine multiplies the input force to accomplish work. The input force necessary to accomplish the work is reduced and the distance through which the reduced input force must be applied is increased by the same factor

mech advantage of an inclined plane

simple machines

Inclined plane, wedge, wheel and axle, lever, pulley, and screw

efficiency

thermal equilibrium

When systems have the same kinetic energy and thus the same temperature. No heat transfer

temperature

thermal expansion

isolated system

Exchange nothing with surroundings

closed system

Exchange only matter with surroundings

open system

Exchange energy and matter with surroundings

state functions

Pathway independent and are not themselves defined by a process. Pressure, density, temp, volume, enthalpy, internal energy, gibbs free energy, and entropy

process functions

Describe the pathway from one equilibrium state to another. Work and heat

1st law thermo

heat

specific heat

heat of transformation

processes with constant variables

Constant Variable: Isobaric: Pressure is constant, P = 0

Isothermal: Temp is constant, T = 0

Adiabatic: No heat is exchanged, Q = 0

Isovolumetric (isochoric): Volume is constant, V = 0, so Work = 0

work of a gas

W=-PV

2nd law of thermo

In a closed system, up to and including the universe, energy will spontaneously and irreversibly go from being localized to being spread out

entropy

A measure of how much energy has spread out or how spread out energy has become

Fluids

Substances that flow and conform to the shape of their containers, includes liquids and gases. They can exert perpendicular forces but not shear forcess.

Solids

Do not flow. They maintain their shape regardless of their container.

Density

Pressure

Absolute Pressue

Gauge Pressure

Pascal’s Principle

Hydraulic Machines

Operate based on the application of Pascal’s principle to generate mechanical advantage

Archimedes’ Principle

Specific Gravity

Cohesive vs Adhesive

Fluids experience cohesive forces with other molecules of the same fluid and adhesive forces with other materials

Surface tension

Cohesive forces give rise to surface tension

Viscosity

A measure of a fluid’s internal friction. Viscous drag is nonconservative

Laminar FLow

Smooth and orderly

Turbulent flow

Rough and disorderly

Poiseuille’s Law

Flow rate

Q = Volume/time = Av

Continuity Equation

Bernoulli’s Equation

Venturi Effect

The velocity of a fluid passing through a constricted area will increase and its static pressure will decrease

Circulatory System fluid flow

Breathing flow

Inspiration and expiration create a pressure gradient not only for the respiration system, but for the circulatory system too.

Alveoli flow

Air at the alveoli has 0 speed

Coulomb

SI unit of charge

Proton vs electron

Protons have a positive charge and electrons have a negative charge. Both protons and electrons possess the fundamental unit of charge e=1.6×10^19 C. Different masses

Attraction and repulsion

Opposite charges exert attractive forces, and like charges exert repulsive forces

Conductors

Free and uniform passage of electrons when charged

Insulators

Resist the movement of charge and will have localized area of charge that don’t distribute over the surface of the material

Coulomb’s law

Electric field

Field lines

Used to represent the electric field vectors for a charge. + charge would move away from a positive charge and toward negative charge. North to south. Stronger field when closer

Equipotential lines

A line on which the potential at every point is the same. Always perpendicular to the electrical field lines. Work is only done when one charge is moved between equipotential lines.

Electric dipole

Net torque

Dipole moment

Product of charge and separation distance p=qd

Electric potential energy

Electric potential

Test charge

Magnetic field

Diamagnetic materials

Possess no unpaired electrons and are slightly repelled by a magnet

Paramagnetic materials

Possess some unpaired electrons and become weakly magnetic in an external magnetic field

Ferromagnetic materials

Possess some unpaired electrons and become strongly magnetic in an external magnetic field

Characteristics of Magnetic Fields

Lorentz Force

Sum of electrostatic and magnetic forces acting on a body