Physics and Math Flashcards
Vectors
Physical quantities with both magnitude and direction
Ex: force, velocity
Scalars
Physical quantities that have magnitude, but no direction
Ex: mass, speed
Average velocity
‘v’ = Δx / Δt
Acceleration
The rate of change of and object’s velocity
a = Δv / Δt
Linear motion equations
v = vo + at
x = vo(t) + 1/2a(t^2)
v^2 = (vo)^2 + 2ax
‘v’ = (vo + v) / 2
x = ‘v’t = ( (vo + v) / 2)t
Vertical component of velocity
v = vsinθ
Horizontal component of velocity
v = vcosθ
Static friction
The force that must be overcome to set an object in motion
0 ≤ fs ≤ (µs)N
Kinetic friction
Opposes the motion of objects moving relative to each other
fk = (µk)N
Newton’s first law
A body in a state of motion or at rest will remain in that state unless acted upon by a net force
Newton’s second law
When a net force is applied to a body of mass m, the body will be accelerated in the same direction as the force applied to the mass.
F = ma
N =
kg(m) / s^2
Work
For a constant force F, acting on an object that moves a displacement of d, the work is W = Fdcosθ
For a force perpendicular to the displacement, W = 0
Joule =
N(m)
Power
P = W / Δt
Kinetic energy
1/2mv^2
Newton’s third law
If body A exerts a force on body B, then B will exert a force back onto A that is equal in magnitude and opposite in direction
Fb = -Fa
Newton’s law of gravitation
All forms of matter experience an attractive force to other forms of matter in the universe
F = G(m1)(m2) / r^2
Mass vs weight
Mass: a scalar quantity that measures a body’s inertia
Weight (Fg): a vector quantity that measures a body’s gravitational attraction to the earth
Fg = mg
Uniform circular motion
ac = v^2 / r
Fc = mv^2 / r
Potential energy
U = mgh
Total mechanical energy
E = Pe + Ke
E = U + K
Work-energy theorem
Relates the work performed by all forces acting on a body in a particular time interval to the change in energy at that time
W = ΔE
Conservation of energy
When there are no nonconservative forces (such as friction) acting on a system, the total mechanical energy remains constant: ΔE = ΔK + ΔU = 0
Linear expansion
The increase in length by most solids when heated
*When temperature increases, the length of a solid increases “a Lot”
ΔL = αLΔT
Volume expansion
ΔV = βVΔT
Conduction
The direct transfer of energy via molecular collisions
Convection
The transfer of heat by the physical motion of a fluid
Radiation
The transfer of energy by electromagnetic waves
Specific heat
Q = mcΔT
- Can only be used when the object does not change phase
Q > 0 means heat is gained, and vise versa
Heat of transformation
The quantity of heat required to change the phase of 1g of a substance
Q = mL
First law of thermodynamics
ΔU = Q - W
Adiabatic
(Q = 0)
ΔU = -W
Constant volume
(W = 0)
ΔU = Q
Isothermal
(ΔU = 0)
Q = W
Second law of thermodynamics
In any thermodynamic process that moves from one state of equilibrium to another, the entropy of the system and environment together will either increase or remain unchanged
Density
(p) = m / V
Specific gravity
(p)substance / (p)water (no units)
(p)water = 10^3 kg / m^3