Diffraction Grating

1) If a diffraction grating has 6,000 grooves per centimeter, to what angle will the first order constructive interference "line" of the Hydrogen Alpha (red) emission be diffracted? 2) Atoms of the hydrogen gas enveloping a particular star absorb the Hydrogen Alpha wavelength from the white light emanating from the surface of the star and reemit that color in random directions, causing the spectrum received by observers on Earth to have a dark line due to the missing light. (Discovered by Joseph Fraunhoffer) Suppose the measured wavelength of the dark line is found to be 6555 Angstroms. Is the radial motion of the star toward or away from Earth? Compute how fast the star is moving rela... click for more

Nuclear physics

1. An alpha particle is fired at a sheet of gold with a kinetic energy of 4.62E-13 joules. Knowing that each gold nucleus has 79 protons, about how close will the alphas come to the nucleus? 2. If the binding-energy-per-nucleon for an alpha particle is 61.0 MeV, what is the total binding energy of the alpha? Give you answer is MeV. 3. Radioactive phorsporous-32 has been used to study bone metabolism and for the treatment of blood diseases. What is the activity of a sample of 12.2x10^16 atoms if it has a half-life of 109 days?

Determining the final mass of a cup using calorimetry.

A 150 gram Aluminum calorimeter cup contains 320 grams of water at 22 degrees Celsius. Steam at 100 degrees Celsius is routed into the calorimeter until the temperature of the cup and its contents reaches 50 degrees Celsius. What is the final total mass of the cup and its contents?

Like charges on two identical balls

Two identical metal balls bear the same amount and sign of electric charge because they have been touched together. The mass of each ball is 2.00 grams. One ball is mounted on an insulating post. The other ball is suspended from a bifilar silk thread suspension system so that it can move on a 0.500 meter radius. When the two balls are 0.0500 meters from each other in the same horizontal plane, the suspension makes an angle of 30.0 degrees from the vertical. What is the charge (in Coulombs) on either of the balls? (I have drawn a picture of the apparatus, but I'm not sure if it is correct - how can they be in the same horizontal plane @ 30 degrees and still swing and touch?)

The potential difference across a cell.

The electrical resistance of a particular electrolytic cell is 5.00 Ohms. A potential difference of 50.0 volts is applied across the cell. If the cell is a copper cell, how much time will be required for 63.54 grams of copper to be deposited on the negative electrode? (Assume the valence of copper is +2).