A wire has a cross-sectional area of 0.10 mm2. If there are 4.0 ...

[geodog55]

A wire has a cross-sectional area of 0.10 mm2. If there are 4.0  1028 atoms per cubic meter in this wire, and if each atom contributes 2 free electrons,
 
  what is the drift velocity of the electrons when the current in the wire is 6.0 A? (e = 1.60  10-19 C)
  A) 0.0047 m/s B) 0.94 m/s C) 0.019 m/s D) 0.0092 m/s

Question 2

A sand mover at a quarry lifts 2,000 kg of sand per minute a vertical distance of 12 meters. The sand is initially at rest and is discharged at the top of the sand mover with speed 5 m/s into a loading chute.
 
  At what minimum rate must power be supplied to this machine? A) 524 w
  B) 3.92 kw
  C) 6.65 kw
  D) 4.34 kw
  E) 1.13 kw

[Yixagurpuldink]

Answer to Question 1

A

Answer to Question 2

D