Using Wein's Law and Planck's quantum equation.

1) The temperature of the surface of the Sun is 5800 K. Using Wein's Law, compute the wavelength of the color of light at which the Sun has its greatest Emissive Power. Describe this color verbally. 2) Use Planck's quantum equation to compute the energy of the "photons" of the light for the color whose wavelength was identified in part one. 3) Compute the energy of photons of light at opposite ends of the visible spectrum: Deep Red: wavelength 7000 Angstroms Violet: wavelength 4000 Angstroms

Calculating the radius of an electron in a magnetic field. Cathode/potential difference

Electrons from a hot cathode move ("fall") through a potential difference of 100.0 volts and then enter the uniform magnetic field between the coils of a Helmholtz set. The coils have radius and separation of 0.150 meters. Each coil has 200 turns. The current through the coils is 0.500 Amperes. Using published values for the mass and charge of the electron, compute the radius of the circular path upon which the electrons will move while in the magnetic field. (Assume the electron beam enters the magnetic field at 90 degrees to the flux density.) I ask this question before and did not follow the tutor. In class we are using B=8N(#of coil turns)*4piE-7*i(current)/5*sq.root of 5*A(radius/sep... click for more

time dilation

Two observers agree to test time diliation. They use identical clocks, and one observer in frame s' moves with speed v=0.6c relative to the other observer in s. When their origins coincide, they start thier clocks. They agree to send a signal when their clocks read 60 minutes and to send a confirmation signal when each receives the other signal. (a) When does the observer in s receive the first signal from the observer in s'? (b) When does he receive the confirmation signal? (c) Make a table showing the times in s when the observer sent the first signal, received the first signal, and received the confirmation signal. How does this table compare with one constructed by the observer... click for more

Object/Image relationships

An object is placed 15.0 cm from mirror whose focal length is 5.0 cm. The object is 6.0 cm high: what is the size of the image?

Calculating the time it takes for two runners at different speeds to cross each other.

It's a sunny Sunday afternoon, about 17 degrees and you are walking around a lake enjoying the early signs of spring. The sidewalk is crowded with runners and walkers. You notice a runner approaching you wearing a t-shirt with writing on it. You read the first two lines, but are unable to read the third and final line before he passes. You wonder, "Hmmm, if he continues around the lake, I bet I'll see him again, but should I anticipate the time when we'll pass again." You look at your watch and it is 3:07 p.m. You recall the lake is M miles in circumference. You estimate your walking speed at 3 miles per hour and the runner's speed to be about 7 miles per hour. What is the time you need to w... click for more