Name:_______________________

Quiz 11

12/13/2005

Ch. 28

1) A space ship travels by earth at .92c as measured on the earth.  It emits a particle beam in the direction of its motion with a speed of .98c as measured on the earth.

a) What is the speed of the particle beam as measured on the ship?

b) If the ship emits a light beam what is the speed of the beam as measured on the ship? What is the speed as measured on the earth?

2) A 0.5kg ball of clay traveling at 0.98c collides with identical ball at rest.   If the two balls stick together after the collision, what is their final speed?  What would the final speed be classically (i.e. Ignoring relativistic effects)?

Name:_______________________

Quiz 12

12/13/2005

Ch. 29

Useful number(s):            c=3.00x108 m/s, h=6.626x10-34 J·s

1)  A beam of electrons hit a double slit with separation 10nm and produces a 3rd order minimum 1μm above the central maximum on a screen which is a distance 100m away from the slit.     What is the momentum of the electrons?

2) A red LED (Light Emitting Diode) emits a 1Watt, 690nm wavelength light beam.  The beam shines on a screen.  How many photons hit the screen during a 1 second interval?