An alpha particle (a helium nucleus, having charge +2e and mass ...

[faduma]

An alpha particle (a helium nucleus, having charge +2e and mass 6.64  10-27 kg) moves head-on at a fixed gold nucleus (having charge +79e).
 
  If the distance of closest approach is 2.0  10-10 m, what was the speed of the alpha particle when it was very far away from the gold? (k = 1/40 = 9.0  109 N  m2/C2, e = 1.60  10-19 C)
  A) 2.3  105 m/s
  B) 4.6  105 m/s
  C) 2.3  106 m/s
  D) 4.6  106 m/s

Question 2

In a double slit experiment, a beam of electrons strikes a pair of slits.
 
  The slits are 15 m apart, and the first interference maximum lies at an angle of 0.50 rad from the center of the interference pattern. What is the momentum of the incoming electrons? (h = 6.626  10-34 J  s, mel = 9.11  10-31 kg)
  A) 8.8  10-23 kg  m/s
  B) 1.1  10-23 kg  m/s
  C) 2.2  10-23 kg  m/s
  D) 4.4  10-23 kg  m/s
  E) 6.6  10-23 kg  m/s

[elyse44]

Answer to Question 1

A

Answer to Question 2

A

[faduma]

Gracias!

[billybob123]

TYSM