When a propeller airplane takes off, how is momentum conserved? ...

[kodithompson]

When a propeller airplane takes off, how is momentum conserved?
 a. Momentum is not conserved, because the airplane goes from being still to moving.
  b. Momentum is conserved only because the earth moves as the airplane takes off.
  c. Momentum is conserved because molecules in the air move as the propeller pushes them.
  d. Momentum is conserved because molecules in the air move on average in all directions.
  e. Momentum is conserved because another airplane has to take off from the other side of the earth at the same time.

Question 2

If two cars are tangled up with each other after an accident that means:
 a. since they moved together, the law of conservation of momentum did not apply.
  b. since they are attached to each other, they stopped moving altogether and the momenta went to zero.
  c. analyzing the history of the accident and the initial momenta will be easier.
  d. analyzing the history of the accident and the initial momenta will be more difficult.
  e. the cars needed to have been going in the same direction to get useful information by examining skid marks.

[soda0602]

Answer to Question 1

c

Answer to Question 2

c

[kodithompson]

TYSM

[peter]

Excellent