Which of the following is an example of changing the impulse of a collision? question 2 options: a boxer turning his head while being punched. a truck smashing into two-layered retaining wall. removing mass from a ship before it collides with an iceberg. a sugar-glider slowing down mid-air before hitting the ground.

By definition, Momentum = Mass x Velocity.

Let us examine the given statements, and decide whether the impulse of the momentum is either LOWERED, INCREASED, or UNCHANGED.
 
Case 1: A boxer turns his head while being punched.
By turning his head away from the incoming punch, the boxer lowers the
velocity with which the punch is delivered.
LOWERED

Case 2: A truck smashes into a two-layered retaining wall.
Neither the mass nor the velocity of the truck changes before impact.
UNCHANGED

Case 3: Mass is removed from a ship before it collides with an iceberg.
By removing mass from the ship, the momentum is lowered.
LOWERED

Case 4: A sugar-glider slows down in mid-air before hitting the ground.
By lowering the velocity, momentum is lowered.
LOWERED

Does this your question?