OAT Physics Formulas

Velocity

v=Δd/Δt (m/s)

Acceleration

a=Δv/Δt (m/s²)

Force

F=ma (N)

Newton

kg x m/s²

Work

Fd (J)

KE

½mv² (J)

PE (gravitational)

mgh (J)

Power (as related to work)

W/∆t=fv (J/s)

J/s

kg x m² / s²

Density

ρ=m/V(volume) (kg/m²)

Pressure

P=F/A (A=πr² for a circle) (Pascals)

Hydrostatic Pressure (measured at a depth d from the surface of a liquid)

pogd (Pascal)

P=measured pressure, g=gravity, d=depth from surface

Pascal

kg/ms²

SI Unit of Length

m (meter)

SI Unit of Mass

kg (kilogram)

SI Unit of Time

s (second)

SI Unit of Electric Current

A (amperes)

SI Unit of Temperature

K (kelvin)

SI Unit of Luminous Intensity

Cd (candela)

Derived Unit of Volume

m³

Derived Unit of Force

N (Newton)

Derived Unit of Energy/Work

J (Joule)

Derived Unit of Power

W (Watt)

Derived Unit of Pressure

Pa (Pascal)

Derived Unit of Charge

C (Coulomb)

Derived Unit of Resistance

Ω (Ohms)

Derived Unit of Capacitance

F (Farads)

Pythagorean Theorem

a² + b² = c²

Vectors

Magnitude and direction

Scalars

Magnitude only

Sin 90°

1

Sin 60°

0.87

Sin 30°

0.5

Sin 0°

0

Cos 90°

0

Cos 60°

0.5

Cos 30°

0.87

Cos 0°

1

Electric Field Strength

E=F/q (N/C)

Force of an Electric Field

F=qE (N/C)

Potential Energy (electric)

PE = qV

Voltage

V = PE/q or V= IR or V= k q/r

Current

I=q/t (Amps)

Resistance

R = V/I or R=p L/A

Capacitance

C=Q/V

Magnetic Field Strength

F=qvBsinθ or B=F/qvsinθ (Tesla)

F=ILBsinθ or B=F/ILsinθ

Sinθ

O/H

Cosθ

A/H

Tanθ

O/A

Displacement

∆x (change in position)

Kinematics

d= vt (no a)

d= v(avg)t (constant a)

d= v0t + ½at² (constant a) (just ½at² when starting from rest)

vf²= v0² + 2ad (constant a - no time given)

Projectile Motion

Time to max ht: 0-v(yi)/g

max ht: =v(yavg)t=v(yi)/2 x tup

total time = 2t(up)

Horizontal displacement: v(x)t(total)

Newton's First Law

An object's velocity remains constant unless a net force is acting upon it (∑F=0, v=constant)

Newton's Second Law

∑F=ma

Newton's Third Law

For every force exerted by one object on a second object, there is an equal but opposite force by the second object on the first

F(2-1)=-F(1-2)

Weight

W=mg (kg)

Force of Gravity

F=G m₁m₂/r² (G=6.67x10⁻¹¹, on earth G=9.8m/s²)

Kinetic Friction

Ff= μ(k)F(N)

Static Friction

Ff= μ(s)mn(normal force)

Centripetal Acceleration

ac= v²/r

Centripetal Force

F= mv²/r=mac

Total Mechanical Energy

E = KE+PE

Conservation of ME

½mv²(i) + mgh(i) = ½mv²(f) + mgh(f) (no work done by conservative forces)

W=∆E (work performed by nonconservative forces, ME is not conserved)

Work Energy Theorem

W=∆KE

Momentum

p=mv

Impulse-Momentum Theorem

F∆t=∆mv

COLLISIONS

SEE SHEET

Angular Displacement

∆θ (d= r)

Angular Velocity

ω=∆θ/∆t (v=r ω)

Angular Acceleration

α=∆ ω/∆t (a=rα)

SEE ROTATIONAL KINEMATICS EQUATIONS

SEE ROTATIONAL KINEMATICS EQUATIONS

Center of Mass

t=m₁x₁ +m₂x₂..../m₁+m₂....

Torque

=Fx(lever arm) or t=Iα

Inertia

I=∑mr² (for pt masses about an axis)

Angular Momentum

L=I ω

Rotational KE

½ I ω²

Specific Gravity

p/p(water)

p(h₂o)

1000kg/m³

Archimedes Principle (Buoyancy Force)

W(fluid displaced)=p(fluid)V(submerged)g

If floating, Fb=Wobject

% submerged

p(object)/p(fluid) x100

Simple Harmonic Motion

x=Acos ωt or x=Asin ωt or x=Acos (ωt + phase shift) (A=amplitude, ω=frequency factor)

Frequency Factor

ω=2πf = 2π/T

Frequency

f = 1/T

T=time period

Spring Frequency Factor

ω=√k/m (whackem)

Pendulum Frequency Factor

ω=√g/l (wiggle)

Spring Force

F = -kx (k=spring constant, x=displacement from eq. position)

Spring PE

½kx²

Hydraulic Jack

F₁/A₁ = F₂/A₂ A₁d₁=A₂D₂

Flow Rate

f = Av (A=CSA - circle = πr²)

Bernoulli's Equation

P₁ + ½pv₂(i) + pgy(t) = P₂ + ½pv₂² + pgy₂

(p1 up, p2 down)

Sound

λf=v

Speed of sound in gases

v = √P/p

Standing Waves

λ(n)=2L/n (pipe open at both ends n=1,2,3,4)

λ(n)=4L/n (pipe open at one end n=odd#)

Intensity (MORE ON SHEET)

I=P/A = P/4π²

Doppler Effect

SEE SHEET - SAME THING 2X

Fo=Fs v±Vo/V±vs

Fo>Fs object and source are moving towards each other

Fs

Elasticity of Solids

modulus x strain

Young's Modulus Stretching/Compression

F/A = Y ∆L/L₀

Shear Deformation

F/A = S ∆X/L₀

Bulk Modulus Volume Deformation

AP = -B∆V/V₀

Coulomb's Law

F = k q₁q₂/r²