i am taking upgrading, and one of the main reasons i failed physics 30 to start with was due to half life. the book can't explain it good enough to me and either could my teacher. so i have a few questions that i would appreciate a starting point for.
How much time elapses before 90% of the...
i have been working on this question for quite a while. no help on google, or my textbook at all.
A hydrogen atom in its ground state is excited to the n=5 level. It then makes a transition directly to the n=2 level before returning to the ground state.
A) What are the wavelengths of the...
An object 5 cm tall is 10 cm from a convace lens. The resulting image is one fifth as large as the object. What is the focal length of the lens?
I have been doing questions involving focal lenght, but not when the resulting image is a fraction of the original image. i do not know where to...
If you hold a 900cm squared plane mirror 45 cm from your eyes and can just see the full length of an 8.5 m flagpole behind you, how far are you from the pole.
I am doing mirror/lens questions and for some reason this one stumps me. I am assuming that the 8.5 m has to be changed to cm...
Hi there, i am facing a question that seem quite simple, i just do not know what formula to use.
the questions is:
A long straight wire carries a current of 2.5 A. Find the magnitude of the magnetic field 25 cm from the wire.
I = 2.5 A
0.025 m
At the fermilab accelerator in Batavia, Illinois, protons having momentum 4.8 x 10^-16 kg x m/s are held in a circular orbit of radius 1 km by an upward magnetic field. What is the magnitued of this field?
r = 1000 m
So i do not understand what are we trying to find here? the question...
A Crossed-field velocity selector has a magnetic field of magnitude 1.0 x 10^-2T. What electirc field strenght is required if 10.0 keV electrtons are to pass through undeflected?
ef - 1.0 x 10^-2
I know it gives magnetic field, except how and what formula do we use to figure out the...
ok thank you.
so if i have a volume of 1.12 x 10^-4, and the equation for volume of a cylinder is (pi)(h)(r^2), i don't get how to computer the length if i do not have a height or a radius? and then i need the length and diameter to get resistance (given at 0.5), how do i get this into...
A battery labeled 12.0 V supplies 1.90 A to a 6.00 ohm resistor
A) what is the terminal voltage of the battery?
B) What is its internal resistance
V = 12.0
R = 6.00
I = 1.90
I think i am to use V = emf - IR for terminal voltage right? however i do not know how to get emf, and IR...
Suppose you wish to fabricate a uniform wire out of 1.0 g of copper (Density of copper is 8.93 x 10^3 kg/m^3). If the wire is to have a resistance of R = .5 ohms, and all the copper is to be used, what will
a) the length and
b) the diameter of this wire?
R = .5
a weight of 1.0...
A light ray initially in water enters a transparent substance at an angle of incidence of 37 degrees, and the transmitted ray is refracted at an an angle of 25 degrees. calculate the speed of light in the transparent substace.
I have my diagram drawn out, however i do not see how to solve for...
A powerful electromagnet has a filed of 1.6 T and a cross-sectional area of .20 m^2. if we place a coil having 200 turns and a total resistance of 20 ohms around the eclectromagnet and then turn off the power to the electromagnet in 20ms, what is the current induced in the wire?
R = 20
N =...
A fiber optic (n = 1.5) is submerged in water (n = 1.33). What is the critical angle for light to stay inside the cable?
i am so confuzed. this is the final question of my paper and i am stuck on a couple questions before this so it is obvious i would get this. i just need a start please.
THe wavelength of a red helium-neon laser light in air is 632.8 nm.
A) what is the frequency? ( i already figured this out to be 4.7 x 10^16)
B) what is its wavelenght in glass that has an index of refraction of 1.50?( i do not know where to or if i have to plug in the refraction into an...
Suppose you wish to fabricate a uniform wire out of 1.0 g of copper (Density of copper is 8.93 x 10^3 kg/m^3). If the wire is to have a resistance of R = .5 ohms, and all the copper is to be used, what will
a) the length and
b) the diameter of this wire?
this has me tottally confuzed...