chapter 12 Flashcards
1
Q
momentum can be changed by…
A
- changing force
- time over which force acts
- both
2
Q
what is impulse
A
force acting on an object to change its momentum
3
Q
what is momentum
A
force that changes velocity of an object
“quantity of motion”
4
Q
if you are stopping an object what must the amount of force and time be like
A
-short time and high force
or
-long time and low force
5
Q
how does your body use impulse to absorb shock
A
- apply eccentric contractions over long time to decrease force on body
- amount of ofrce absorbed is dependent on magnitude of ground reaction forces
6
Q
impulse for changing directions in sport related movements requires…
A
- force must be applied to the person
- high force and short time
- if you increase ground rxn force = increase jnt rxn forces = increase risk of injury
7
Q
what must you do to max momentum of an object
A
max quantity of force over longest period of time
8
Q
how do imulse-momentum ideas apply to human movement
3 of them
A
- best shock absorption = small force over long time
- starting and abrupt changes of direction = large force over short period of time
- greatest change in velocity = large force + long time
