Which can undergo diffraction? A) photons. B) electrons. C) ...

[leo leo]

Which can undergo diffraction?
 
  A) photons.
  B) electrons.
  C) positrons.
  D) all of the above
  E) none of the above

Question 2

For a satellite in orbit around Earth, the product of its speed times the distance from the center of Earth has the same value when the satellite is at the perigee, its closest approach to Earth, and at the apogee, its furthest point from Earth.
 
  Is the product the same at other points on the orbit? Why?

[Briannahope]

Answer to Question 1

Answer: D

Answer to Question 2

No. According to Kepler's second law, equal areas are swept in equal times. For a short time interval, this translates into the product of the perpendicular component of radius times the speed times one-half of the time interval. Since the velocity and the radius are perpendicular to each other only at those two points, the product has that value only at those two points.

[leo leo]

TY

[Briannahope]

You're welcome