Two boys with the same mass jump to the ground out of the same window. Andrew (A) bends his knees when he touches the ground, while Ben (B) keens his knees as rigid as possible. - Do the boys have the same momentum when they touch the ground?

Question

jamesj · Answer

At that very moment, yes, they have the same momentum.

anonymous · Answer

then how does the change in momentum the boys experience when they touch the ground compare?

jamesj · Answer

Well, one changes his momentum very fast, one slow; one applies much more force to their body, one less.

Change in momentum = mass * change of velocity
                                   = mass * acceleration * change in time
                                   = Force                      * change in time