PHYSICS FINAL REVIEW Flashcards
M, k, d, c, m, u, n, p prefixes
Mega, kilo, deci, centi, milli, micro, nano, pico
10^6, 10^3, 10^-1, 10^-2, 10^-3, 10^-6, 10^-9, 10^-12
Sin 0, 30, 45, 60, 90
Sin 0 = 0 Sin 30 = .5 Sin 45 = .7 Sin 60 = .9 Sin 90 = 1
Cos 0, 30, 45, 60, 90
Cos 0 = 1 Cos 30 = .9 Cos 45 = . 7 Cos 60 = .5 Cos 90 = .0
Tan 0, 30, 45, 60, 90
Tan 0 = 0 Tan 30 = .5 Tan 45 = 1 Tan 60 = 2 Tan 90 = undefined
velocity equation
average velocity ⊽= Δx/Δt
Δx = displacement, Δt = change in time
does not account for distance traveled
speed equation
average speed: v= distance/time
accounts for distance traveled
velocity vs speed
speed is a scalar quality, the rate at which an object covers distance; velocity is a vector quality, and the rate at which the position changes
Gravitational force equation
F = GMm / r^2
G= gravitational constant, M= mass 1, m= mass 2, r=distance between center of mass
pay attention to the relationship between r and force
as r doubles, force is divided by four
SI Units
Density Force Pressure Temperature Energy Power Charge Potential Current Resistance Magnetic Field
Density = kg/m^3 Force = N Pressure = Pa Temperature = K Energy = J Power = W Charge = C Potential = V Current = A Resistance = Ohm Magnetic field = Tesla
static friction and kinetic friction equations and application
static friction: fS MAX = ukN
stationary objects
- can experience the minimum static force (0) if the object is resting on a surface with no applied force
- when static friction is overwhelmed the object will move
kinetic friction: fK = ukN sliding objects (sleds, not tires)
Weight equation
Fg (weight) = mg
Acceleration equation
average acceleration
Δv/Δt
- change in velocity over time
- the value of speed/velocity, distance/displacement are interchangeable in this case
Newton’s first law equation
FNET = ma = 0
A body will remain in its motion unless a net force acts upon it
law of inertia
Newton’s second law equation
FNET = ma
Force is equal to change in momentum per change in time
Newton’s third law equation
FAB = -FBA
For every action there is an equal and opposite reaction
Linear motion equations (velocity, displacement, acceleration, and time)
V = V0 + at
final velocity = initial velocity + acceleration*time
x = V0t + 1/2at^2 displacement = initial velocity(time) + 1/2acceleration*time^2
v^2 = v0^2 + 2ax velocity^2 = initial velocity^2 + 2ax
x = vt displacement = average velocity * time
How to analyze projectile motion
analyze the vertical and horizontal values separately
vy will change at the rate of gravity as acceleration
vx will not change
Inclined planes, Force of gravity parallel to plane and perpendicular to plane
Fg (parallel to plane) = mgsinፀ
Fg (perpendicular to plane) = mgcosፀ
Circular motion equation
Fc= mv^2/r
centripetal force = mass * velocity^2 / radius
acceleration is therefore v^2/r
How to draw free body diagrams
make sure to draw for any calculation on forces
What is translational equilibrium
when the vector sum of all the forces acting on an object is zero
constant speed and constant direction, zero acceleration
What is rotational equilibrium
when the vector sum of all the torques acting on an object is zero
constant angular velocity (probably zero)
Equation for kinetic energy
K = ½ mv^2
units of Joules (like all energy)
Equation for gravitational potential energy
U= mgh