Lead has a latent heat of fusion of 2.32 104 J/kg, and a ...

[WWatsford]

Lead has a latent heat of fusion of 2.32  104 J/kg, and a specific heat of 128 J/(kg K), and a melting point of 228C. The ambient temperature is 16C. A 30-g lead bullet hits a solid surface and comes to a complete stop.
 
  What would the velocity of the bullet have to be in order for it to melt completely when it hits the wall, assuming that all its kinetic energy is transformed into heat? A) 207 m/s
  B) 215 m/s
  C) 232 m/s
  D) 273 m/s
  E) 318 m/s

Question 2

What is the thickness of a soap bubble film (n = 1.38 ) that results in a constructive interference in the reflected light if this film is illuminated by a beam of light of wavelength 610 nm?
 
  A) 222 nm
  B) 111 nm
  C) 333 nm
  D) 444 nm
  E) 555 nm

[blakeserpa]

Answer to Question 1

E

Answer to Question 2

B

[WWatsford]

TYSM

[matt95]

Gracias!