A 1000-kg truck moving at 10 m/s that brakes to a stop in 5 s has ...

[vinney12]

A 1000-kg truck moving at 10 m/s that brakes to a stop in 5 s has an average braking force of
 
  A) 1000 N.
  B) 2000 N.
  C) 3000 N.
  D) 4000 N.
  E) 5000 N.

Question 2

You hold a 5-newton rock motionless in your hand. Regarding the forces on this rock,
 
  A) the net force on the rock is zero.
  B) the downward force of gravity is balanced by the upward force of air resistance.
  C) there are no forces of any kind acting on the rock, because it is not moving.
  D) the net force on the rock is 5 newtons, directed downward.
  E) the net force on the rock is 5 newtons, directed upward.

[scottmt]

Answer to Question 1

Answer: B

Answer to Question 2

A