Author Question: An alpha particle (a helium nucleus, having charge +2e and mass 6.64 10-27 kg) moves head-on at a ... (Read 102 times)

faduma · **on:** Jul 29, 2018

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