Etkina Chapter 5 (Momentum) Flashcards
Isolated system: a group of objects that interact with each other but not with ….. the system
external objects outside
mass of an isolated system is the …. of the …. of all objects in the system
sum; masses
law of constancy of mass: when a system of objects is isolated (a .. container), its mass equals the …. of its components and does not … — it remains constant in ….
closed; sum of the masses; change; time
In an open system, change of mass can occur according to this equation: … of system at earlier …. + …. entering or leaving system between the two …. = …. of system at later ….
initial mass; clock reading; new mass; clock readings; final mass; clock reading
mass is a …. quantity → such a quantity is … in an isolated system
conserved; constant
the linear momentum of a single object is the product of its … and ….: p =
mass; velocity; m*v
Vector quantity of momentum is in the same direction as the object’s ….
velocity
SI unit of momentum is
kg *m/s
total linear momentum of a system containing multiple objects is the … of the … of the individual objects
vector sum; momenta
because momentum depends on the velocity of the object, and the velocity depends on choice of …., so different observers will …. for the same object
reference frame; measure different momenta
the momentum of an isolated system is …. For an isolated two-object system: m1vi,1 + m2vi,2 =
constant; m1vf,1 + m2vf,2
momentum of an isolated system can be split into
components
both force and time interval affect momentum– the longer the time interval, the greater the ….. A small force exerted for a long time interval can change the momentum of an object by …. amount as a large force exerted for a short time interval
momentum change; the same
force * time gives us the … of the external force exerted on an object
impulse
the …. under a force-time graph represents impulse
shaded area
we can estimate impulse by drawing a horizontal line that is approximately the …. exerted during the time interval of the impulse
average force
impulse is a …. quantity that points in the direction of the …
vector; force
SI unit for impulse is … = ….
N*s = kg * m/s
impulse =
change in momentum
if several external objects exert forces on a single-object system during a time interval, the sum of their impulses causes a …. of the system object: pf - pi = …. = …
change in momentum; sigma J = sigma F on system (tf - ti)
if the magnitude of the force changes during the time interval considered in the process, we use
average force
if the same amount of force is exerted for the same time interval on a large-mass object and on a small-mass object, the objects will have an equal …. because the same …. was exerted on them → BUT, the small-mass object would have a greater ….
change in momentum; impulse; change in velocity
the change in momentum of a system is equal to the
net external impulse exerted on it
generalized impulse-momentum principle: for a system containing 1+ objects, initial momentum plus sum of … equals the … (law of …)
impulses; final momentum; momentum conservation
the length of the bars are qualitative indicators of the relative magnitudes of
momenta
sum of the heights of the bars on the left plus the height of the impulse bar should equal the sum of the heights of the bars on the right to reflect
conservation of momentum
when a system object collides with another object and stops, the system object travels what is called its …. By estimating …., we can estimate the ….
stopping distance; stopping distance; stopping time interval
