Linear Kinetics 2 Flashcards
What is impulse
a measure of a force applied for a certain amount of time .
The net force acting over some interval of time will cause
a change in momentum of an object
Impulse is the area under a ______ graph
force time
Changes in the momentum of a system depend on
- the magnitude of external forces
2. the time over which the forces act
An impulse can cause a change in ____
momentum
During human movement we are constantly trying to
change the velocity of something
During a squat jump, when is ground reaction force the greatest
lowest body position
Ground reaction force ____ from the lowest body position to the moment of take off
decreases
During a squat jump, when is velocity the greatest?
right before take off
During a squat jump, when is velocity the lowest?
landing
During a squat jump when does the initial dip in velocity occur
When lowering
When measuring using a force plate, if body weight is greater than ground reaction force, what is occuring
a negative change in momentum
What stops the downward motion of a squat jump?
Positive impulse
Negative impulse …. just prior to take off
slows the upward motion of the jumper
Using a force plate, what is the heigh the individual jumps determined by?
the net impulse - difference between the total positive impulse and the total negative impulse
What is friction
the force resisting the relative motion of solid surfaces
What is friction the result of
the interaction of the surface area of objects in contact
What is the science of engineering of interacting surfaces in relative motion called
tribology
As applied force increases force of static friction ____ until
increases until a critical point is reached
The greater the coeeficient of friction the…
less easily one surface will slide on another
What is kinetic friction
once an object is in motion, the frictional force acting on the box is called kinetic friction
As applied force continues to increase, Force of kinetic friction…
continues to increase and is always less than applied force
