The main practical problem associated with building an ...

[nautica902]

The main practical problem associated with building an interstellar ramjet is
 
  A) making the ship large enough to scoop up enough hydrogen fuel given that the density of hydrogen in space is so low
  B) producing enough thrust to accelerate the spacecraft to a high enough speed
  C) separating the matter and antimatter fuels from each other
  D) receiving enough photon energy to propel the craft

Question 2

What change in wavelength is expected when X-rays are scattered at 90?
 
  A) no change at this angle
  B) 4.84  10-3 nm
  C) 2.42  10-3 nm
  D) 1.18  10-3 nm
  E) 3.75  10-3 nm

[blazinlyss]

Answer to Question 1

A

Answer to Question 2

C

[nautica902]

Excellent

[xiaomengxian]

TYSM