Recent content by edoarad

hello, I am supposed to give a short (20-30 mins) lecture to some very smart 2nd year math majors, and i thought about finding an intersting physics topic. my first idea was special relativity, or more specificly deriving E=MC^2 from einsteins assumptions about light's behevior, but in the...

hello, I'm a 12th grader that wants to find a job in the physics field. i was wandering if anyone has an idea for what i can do, without any academic education, that can be both interesting for me and that i can earn a little money doing so? i am basically familliar with meny concepts in physics...

thank you

Homework Statement i need to find the mass of a new found planet at a given radius from the sun (R) and with a given cycle length (T) Homework Equations Kepler and Newton The Attempt at a Solution of course if R and T would fit with keplers third law then there would be no way to...

does the expansion itself redshifts photons (if so, does the expansion affect the photon in his frame of referance?) or is it because the distant object that emits them is seemingly moving away from us (in cases where the expansion is much more dominant of course)? The latter doesn't makes much...

i think I've got it now, thank you.

i thought that the energy from e=mc^2 is simply the energy that can be gained by using the mass, is that wrong?

thank you very much. does a body whose mass has been increased by high temprature acts the same as though he was simply that massive? how hot must something be in order for the added mass not to be neglectable?

i've read that the mass of two objects which is formed when two equal objects collide must be twice the mass of the moving objects, which is grater then the sum of their rest mass. does it really happen in terms of particles? how is it explained? thanks, edo

the only force (besides gravity) is the Normal, which is prependicular to 45 degree slope as you said. i am not sure what you ment by the force on the y axis, velocity? gravity? anyway the sum of the vectors doesn't have to be parallel to the x-axis in order for the ball's velocity to be...

can someone please help me?

just saw the warning, please don't delete my posts :S they are in a close enough format i think..

in a refracting telescope, the lens's diameter is 1.02 m and its focal length is 19.4 m. how long must the telescope be to get an image, 40 times bigger? i would also like to get a link to a site explaining this kind of elementary optics.

Sirius A has an apperant magnitude of -1.5, and his distance from us is 2.6 pc. the sun has an apperent magnitude of -26.8 and a distance of 1 AU. what is Sirius's absolute magnitude? how meny times is Sirius brighter then the sun? m1-m2=-2.5lg(f1/f2) this is the equation I'm supposed...

is it also due to solar wind? if so why is it in a different direction than the gaz tail?