Resolve vectors to solve
momentum in two dimentions
Force and Energy
Force is the change in momentum
F = ma
"the rate of change of
momentum of an object is
directly proportional to the
resultant force which acts on
an object"
F = mv / t
Conservation of Energy
Energy cannot be created or Destroyed. Energy can be
transferred from one form to another but the total amount of
energy in a closed system will not change.
Kinetic Energy
Ek = 1/2 mv^2
Ek = P^2/ 2m
Kinetic Energy is conserved
in Elastic collisions
Circular motion
Radians
Angle in Radians = (2¬ / 360) x
angle in degrees
Angular Speed is the angle
an objet rotates per second
w = 0 / t
v = w r
Frequency and Period
f = 1/ T
w = 2¬ f
T = 2¬ / w
Centripetal Acceleration
F = m v^2 / r
a = r w
a = v^2 / r
F = m w^2 r
Produced by Centripetal Force
Electric and Magnetic Fields
Electrical Fields
Electric field around a charged object
F = k Q1 Q2/ r^2
Force on Q1 is always equal and opposite to Q2
k = 1 / 4¬E
E = permittivity of material
between charges
Radial and Uniform
E= kQ / r^2
E = F / Q
E = V / d
Capacitors
Amount of charge stored per volt
C = Q / V
Charging and Discharging
Q = Q0 e^-t/RC
V = V0 e^-t/RC
I = I0 e^-t/RC
T = RC
Fully Discharged = 5RC
W = 1/2 QV
W = 1/2 CV^2
W = Q^2 / 2C
Magnetic Fields and Forces
∅=BA
ϕ=N∅=BAN
Fleming's left hand rule
F=BIl
F = BIl sin Θ
The force on one metre of wire carrying a current of one
amp at right angles to the magnetic field
Charged particles in magnetic fields
F = Bqv
F = Bqv sin Θ
Faraday's law
The induced e.m.f is directly
proportional to the rate of change
of flux linkage
induced e.m.f =∆Φ/∆t
induced e.m.f = ∆N∅/∆t
Electromagnetic Induction
Lenz's law, the induced e.m.f is
always in such a direction at to
oppose the change it caused