Physics Flashcards
What is the equation for the energy of a photon of light?
E=hf=hc/λ (J/photon)
What is Plank’s constant?
h=6.62 x 10^-34 Js
What is the equation for the speed of light?
c=fλ= 3 x 10^8
What direction to negatively charged particles move in an electric field?
Opposite direction of electric field lines
What is the equation for electric field produced by source charge Q?
E= kQ/r^2 direction= direction a +q would move in presence of source charge Q
What is the equation for electrostatic force between 2 charges q and Q?
F=kQq/r^2
What is the equation for electric potential energy?
U=kQq/r
What is the equation for electric potential?
V=kQ/r
Electrons moves from higher potential (+) to lower potential (-)
What is the value of k, Coulomb’s constant?
k=8.99 X 10^9 Nm/C^2
What is the unit conversion for pressures?
1.013x10^5Pa = 760 mmHg = 760 torr = 1 atm
What is the equation for the charge stored in a capacitor?
Q=VC
What is the equation for capacitance?
C=ake/d
What is the energy stored in a capacitor?
U=1/2QV^2 = 1/2CV^2 = Q^2/2C
When the battery is connected to the capacitor…
V= constant; Q= changing
When the battery is disconnected to the capacitor…
V= changing; Q= constant
Begin to discharge–> both start changing
Sound Intensity
I= 10dblog(I/Io) Io= 10^-12 multiplying by 10= +10dB dividing by 10= -10dB multiplying by 1000= +30dB sound waves spread out in all direction in a surrounding sphere; sound intensity decreases by a factor of r^2
What is Hooke’s Law?
(restoring force) F= kx
F vs displacement (x) is a linear relationship with k= slope
What is the potential energy in a spring?
PE= 1/2kx^2
G(unit)=
10^9
