MCAT Physics Equations/Concepts

Kinematics Equations

Force of Gravity Between Two Objects

Units of G = N∗m²/kg²

Kinetic Friction

Static Friction

Uniform Circular Motion - Velocity

Velocity vector is constantly changing and is tangential to the circle of motion

Centripetal Acceleration

The acceleration vector always points toward the center of the circle and constantly changes direction as the object moves.

Centripetal Force

Torque

θ = angle between F and the lever arm. (Max force at sin90° = 1) By convention, clockwise rotation is negative, counterclockwise rotation is positive.

Work-Energy Theorem

Kinetic Energy

SI Unit for KE (all energy) = Joules = kg∗m²/s²

Work

θ = angle between F and the displacement vector. Only forces (or components of forces) that are parallel or anti-parallel to the displacement vector will do work. Max work at cos0 or cos180 = 1 or -1.

Gravitational Potential Energy

Conservation of Energy

Power

SI Unit for Power = Watt = J/s = Energy consumption, transfer or transformation per unit time

Momentum

Momentum is measured in kg∗m/s

Conservation of Momentum

For elastic and inelastic collisions

Completely Inelastic Collision

Hooke's Law

F = restoring force, k = spring constant, x = displacement from natural length. Larger k = stiffer spring, and larger magnitude of restoring force for a given displacement. F is always opposite the direction of displacement.

Simple Harmonic Motion - Period/Frequency

Simple Harmonic Motion - Angular Frequency - Mass and Spring

One revolution = 2π radians. ω only depends on k and m, not x! Two springs with identical k and m values will have the same ω, regardless of x.

Simple Harmonic Motion - Elastic Potential Energy of a Spring

where x is displacement from equilibrium. Upon release, the spring will accelerate in proportion to the restoring force and PE will be converted to KE.

Simple Harmonic Motion - Angular Frequency - Pendulum

ω only depends on g and L, not m or θ! Two pendulums with the same length will have the same ω regardless of m or initial θ.

Simple Harmonic Motion - Restoring Force - Pendulum

F = restoring force, m = mass attached to pendulum, g = acceleration due to gravity, θ = angle between pendulum arm and the vertical. F acts tangential to arc of circle. Max F and a at max θ.

Simple Harmonic Motion - Potential Energy - Pendulum

Density

Units = kg/m³

Specific Gravity

if >1 will sink, if <1 will float in liquid water. If <1 SG = % of object that is submerged.

Pressure

Unit = N/m² = Pascal (Pa)

Fluid (Gauge) Pressure

Absolute Pressure

Pascal's Law

When a change in pressure is applied to an inclosed fluid, that pressure change will be transmitted undiminished to every portion of the fluid and to the walls of the vessel.

Coulomb's Law

Unit = Newtons

Electric Field (w/Test Charge)

Unit = Newtons/Coulomb (or Volts/meter)

Electric Field (w/Point Charge)

Unit = Newtons/Coulomb (or Volts/meter)

Electric Potential

Unit = Volts (Joules/Coulomb). Positive charges move from high potential to low potential, negative charges move from low potential to high potential.

Current

Unit = Coulomb (charge/second)

Ohm's Law

Electrical Power

The amount of power dissipated by a resistor.

Resistors in Series

Vs = V₁ + V₂ + V₃ + etc.

Resistors in Parallel

Vp = V₁ = V₂ = V₃ = etc.

Capacitance

Unit = farad (F = Coulomb/Volt)

Electric Field - Parallel Plate Capacitor

In this case E is measured in Volts/meter

Electric Potential Energy Stored in a Capacitor

Dielectric Constant

Capacitors in Series

Capacitors in Parallel

Magnetic Field Lines

Magnetic Field (Straight Current Carrying Wire)

Magnetic Field (at Center of Wire Loop)

Remember - this is the field at the center of a loop.

Magnetic Field - Orbit Radius

Remember even though the equation suggests otherwise, increasing β will not increase the velocity, it will just decrease the radius.

Magnetic Force - Point Charge Moving through Field

Magnetic Force - Current Carrying Wire in Magnetic Field

Newton's Third Law

Archimede's Principle

AC Current

Work Function

Sound Level

Young's Modulus

AC Current

Alpha Decay

Beat Frequency

Bernoulli's Equation

Beta Minus Decay

Beta Plus Decay

Blackbody Spectrum

Bohr Angular Momentum

Bulk Modulus

Center of Gravity

Center of Mass

Conservation of Kinetic Energy

Conservation of Momentum

Continuity Equation

Critical Angle

Critical Velocity of a Fluid

Difference in Sound Level

Diffraction

Dipole Electric Field

Dipole Torque

Dipole Voltage

Doppler Effect

Efficiency

Electron Capture

Energy of a Photon

First Law of Thermodynamics - Special Cases

First Law of Thermodynamics

Closed Pipe - Wavelength and Frequency

Open Pipe (and Strings/Standing Waves) - Wavelength and Frequency

Gamma Decay

Gravity

Hydrogen Energy Levels

Heat of Transformation

Impulse

Index of Refraction

Wave Interference

Voltage of a Battery (When Internal Resistance is Present)

Law of Reflection

Lens Power

Magnification (for Multiple Lenses Not in Contact)

Focal Length and Power (for Multiple Lenses in Contact)

Lensmaker's Equation

Log Rules