A horizontal 100-N force exerted against a 1000-N block causes ...

[j.rubin]

A horizontal 100-N force exerted against a 1000-N block causes the block to slide on a level surface with constant velocity. The friction force on the block must be
 
  1) zero.
  2) 100 N.
  3) 1000 N.
  4) greater than 1000 N.
 
  In this case the pushing force and the friction force are
  5) equal but oppositely directed.
  6) an action-reaction pair.
  7) both of these.
  8) none of these.

Question 2

A skydiver jumps through the air from a high-flying plane. As her velocity of fall increases, the net force acting on her
 
  1) increases also,
  2) decreases,
  3) remains unchanged,
 
  and her acceleration
  4) increases.
  5) decreases.
  6) remains unchanged.

[jesse.fleming]

Answer to Question 1

Answer: 2, 5

Answer to Question 2

Answer: 2, 5

[j.rubin]

TYSM

[shewald78]

Excellent