A plane is headed eastward at a speed of 156 m/s. A 20.0 m/s wind is blowing southward at the same ...

A plane is headed eastward at a speed of 156 m/s. A 20.0 m/s wind is blowing southward at the same time as the plane is flying. The velocity of the plane relative to the ground is
 
  A) 157 m/s at an angle 7.31 south of east.
  B) 157 m/s at an angle 7.31 east of south.
  C) 155 m/s at an angle 7.36 south of east.
  D) 155 m/s at an angle 7.36 east of south.
  E) 157 m/s at an angle 7.36 south of east.

Question 2

A mixture of helium and another gas diffuses through a porous barrier. The helium diffuses 3.16 times faster than the other type molecule. Identify the other gas.
 
  What will be an ideal response?

Question 3

A 0.600-mm diameter wire stretches 0.5 of its length when it is stretched with a tension of 20 N. What is the Young's modulus of this wire?
 
  A) 5.66  1010 N/m2
  B) 3.54  109 N/m2
  C) 1.41  1010 N/m2
  D) 6.43  109 N/m2
  E) 2.78  109 N/m2

Question 4

For total internal reflection to take place, light must go from a medium of lower index of refraction to a medium of higher index of refraction.
 
  Indicate whether the statement is true or false