As you stand by the side of the road, a car approaches you at a ...

[K@]

As you stand by the side of the road, a car approaches you at a constant speed, sounding its horn, and you hear a frequency of 80.0 Hz.
 
  After the car goes by, you hear a frequency of 60.0 Hz. What is the speed of the car? Assume that he speed of sound in air is 343 m/s.
  A)
 
  64 m/s
 
  B)
 
  49 m/s
 
  C)
 
  16 m/s
 
  D)
 
  36 m/s
 
  E)
 
  25 m/s

Question 2

The tensile strength for a certain steel wire is 3000 MN/m2. What is the maximum load that can be applied to a wire with a diameter of 3.0 mm made of this kind of steel?
 
  A)
 
  64 kN
 
  B)
 
  9.0 kN
 
  C)
 
  42 kN
 
  D)
 
  85 kN
 
  E)
 
  21 kN

[Yixagurpuldink]

Answer to Question 1

B

Answer to Question 2

E

[K@]

Gracias!

[carojassy25]

TYSM