Volume of the sphere = 4/3 pi r^3 = 2.14×10^9 m^3
Volume of the cone = pi r^2 h/3 = 0.047 m^3
ratio = 2.196 * 10^-11
2.196 * 10^-11 * 2.77*10^20 =6.1*10^9 protons!
Thanks!
Homework Statement
(a)Estimate the number of photons per second emitted by a 100-W lightbulb, assuming a photon wavelength of 550nm.(b) A person can just see this bulb for a distance of 800m, with the pupil dilated to 7.5mm. How many photons per second are entering the pupil?
Homework...
Homework Statement
Find the smallest grating spacing that let's you see the entire visible spectrum.
400nm to 700nm comprises the visible light spectrum.
no other information is given.
Homework Equations
nλ=d sin θ
The Attempt at a Solution
I am not sure how to start as all i have been given...
Well in order to solve for the time I need to use charge to use the Q=Qocos(ωt) and rearrange to solve for time.
so i worked out the math,
my new voltage at 1/2 original energy V=√(2E/C) = 6.36 volts
new charge at 1.2 energy Q=CV= (4700e-6 * 6.36) = 0.0299
initial charge Q=CV=(4700e-6 * 9) =...
energy of a capacitor varies with Voltage which is also a factor of charge...
so i need to solve for the voltage of the capacitor when energy is 1/2 of initial energy, then plug that into the charge equation, right?
Let me see if what I am thinking makes sense here for solving current. U=1/2 LI2 for the inductor, U=1/2 CV2 for the capacitor. So does U=U
1/2 CV2 =1/2 LI2 . By doing this and rearrangeing to solve for I i have I=√((CV2)/L) which = ~ 0.5A. IS this correct? or am i way off?