Physics: Momentum+ Collisions
Why is more impulse delivered during a collision when bouncing occurs than during one when it doesn't?
Change in momentum is greater so the impulse is greater
Which has a greater momentum: a 2-ton rollercoaster moving at 50km/hr or a 2.5 ton truck moving at 35 km/hr? a. they're the same b. neither c. truck d. rollercoaster
D
two objects are stuck together and explode apart, each moving separately afterwards; an internal impulse or force acts in order to propel the different parts of a connected system
Explosions
interaction in which the objects of the system are initially at rest before the parts interact and fly apart because of the release of energy stored within the system
Explosive interaction
True or false? Momentum cannot be shifted between two objects.
False B
Why is it advantageous for a boxer to ride with the punch? Why should he avoid moving into an oncoming punch?
Greater time means less force; less time means greater force
impulse will cause a change in a object's momentum;
Impulse-Momentum Theorem
principle stating that the total linear momentum of an isolated system remains constant regardless of changes within the system.
Law of conservation of momentum
inertia in motion; an object in motion wants to stay in motion in a straight line, the product o the mass of an object and the velocity of the object; determined by the mass and the velocity of the object in motion
Momentum
where does the Law of Conservation of Momentum come from?
Newtons 3rd law
what forces affect how much an object's momentum changes
acting force, timeinterval
what does the impulse momentum theory state
an impulse will cause a change in an object's momentum
What would you have to do to increase momentum?
apply a greater force (follow through)
What would you have to do to decrease momentum?
apply a longer contact time to reduce the force (padded floor when faling)
how does the impulse that acts on a moving object that stops when it hits a barrier compared to the impulse on the same moving object if it bounces off the barrier
bounced object requires a larger impulse than a stopped object, 2nd impulse on object when it bounces to get it moving again
What are three examples of explosions?
bullet fired from a gun, throwing a ball, rocket launch
What are five examples of elastic collisions?
bumper cars, hitting a baseball. playing pool, bowling, air hockey
In terms of momentum conservation, why does a cannon recoil when fired?
cannon's momentum must be equal and opposite to that of the cannonball
What are four examples of inelastic collisions?
car crash, bullet fired into a block of wood, figure skating, football tackle
Does impulse equal momentum, or a change in momentum?
change in momentum
if an object accelerates, momentum will not be constant but the mass does not change.
changing momentum
momentum is transferred from one object to another
collision
Momentum is conserved, because the total momentum of both objects before and after the collision is the same; Total momentum of all object interacting with each other remain constant regardless of the forces between them
conservation of momentum
absence of an outside force, the momentum of a system will remain unchanged. pi = pf , in any collision or explosion, the total momentum remains
conservation of momentum
in the absence of an outside force, the momentum of a system will remain unchanged Momentum before= momentum after pi= pf
conservation of momentum
says that in the absence of external forces, the momentum of a system remains unchanged
conservation of momentum
how is momentum related to mass and velocity
directly proportional
Momentum is ________ related to mass and _________ related to the velocity of the object. For a large momentum, you will need a ________ mass and a fast __________. It will be harder to stop this object because it has a lot of ___________. If velocity is constant, then momentum will be constant as well. Fnet= ____ N a= 0 m/s2
directly, large, velocity, momentum, 0
impulse-momentum theorem: __ and __ are kept constant, the larger the __, the larger the change in __
duration,mass, force, velocity
two objects before, they hit and bounce off each other, pi= pf
elastic collision
two objects before, they hit and bounce off each other;All the energy is conserved after the objects collide into one and other; momentum and kinetic energy are conserved example: rubber balls
elastic collision
Collisions in which colliding objects rebound without a lasting change in shape or sound or heat generation
elastic interaction
Examples of Conservation of Momentum: A Ball hits a baseball- the bat exerts a force on the ball, the ball must exert an ________ but _______ force on the bat. Both the bat and the ball receive an ______. The momentum lost by the bat is ________ to the ball. So the bat _______ down, the ball _______ up!
equal, opposite, impulse, transferred, slows, speeds
two objects are stuck together and explode apart, each moving separately afterwards action/reaction: recoil collisions pi=pf
explosions
are initially together at rest and then fly apart only __ is conserved
explosive
term often used to describe the force when one object hits another
impact
combination of force and time interval over which the force is applied or duration
impulse
force is applied over a period of time, it will change an object's momentum
impulse
product of the average force exerted on an object and the time interval through which it acts; product of the force acting on a system/time interval during which the force acts
impulse
when a force is applied over a period of time, it will change an objects momentum
impulse
when a force is applied to an object over a period of time, resulting in a change in the object's momentum
impulse
states that the impulse on an object is equal to the change of the momentum that it causes; impulse causes and is equal to the resulting change in momentum and in the same direction as the change of momentum
impulse momentum theorem
to cause a change in motion of an object, an __ is applied and the __ will equal the resulting change in the __ of an object aka
impulse, impulse, momentum impulse-momentum theorem
impulse will change in an object's momentum -if we apply a force over a period of time, it changes our momentum -a force applied to a an object over a period of time causes a mass to change its velocity
impulse-momentum theorem
collide and stick together only __ is conserved
inelastic
two objects before, they hit, stick together, and continue to move as one;two objects collide and do not bounce away from each other. -high speed car collision, Two billiard balls collide
inelastic collision
two objects before, they hit, stick together, and continue to move as one, pi=pf
inelastic collisions
collision in which the colliding objects become tangled or coupled together, distorted and/or generate heat or sound during the collision
inelastic interaction
What are examples of reducing the force?
jumping from a height, catching a water balloon, airbags
high impulse=?
large change in momentum
An high impulse= ______ change in momentum. Increasing/Decreasing Momentum causes a change Velocity Increase= Positive Force; Decrease=Negative Force More Mass= ______ Momentum More ______= more momentum
large, more, speed
Impulse-Momentum Theorem -A high impulse implies a ______ large in momentum a low impulse implies a ______ change in momentum
large, small
states that momentum of any closed system with no net external force acting or it does not change; a closed and isolated system, the momentum of the system before the interaction among the system parts is equal to the momentum of the system after the interaction
law of conservation of momentum
What is the formula for elastic collisions?
m1+m1+m2v2=m1v1f+m2v2f
What is the formula for inelastic collisions?
m1v1+m2v2i= (m1+m2)vf
momentum is a product of __ and __ equation: ∆p=∆(mv)
mass, velocity
factors that affect an object's momentum large momentum if object has __, ___ __ or both
mass, velocity, mass, high speed
Impulse-momentum theorem: __ and change in __ kept constant, (ie coming to a __) __ and __ __ change in opposite directions the __ the time interval, the __ the required force
mass, velocity, stop, force, time interval, greater, smaller
impulse equals change in _________.
momentum
inertia in motion; mass of an object multiplied by its velociy
momentum
What does it mean to say that momentum is conserved?
momentum before the collision is the same as the momentum after
What happens when an object accelerates?
momentum will not be constant, mass will not change and velocity must change
__ equals the momentum of the object __ an impulse minus the momentum __ the impulse
momentum, after, before
does the momentum change during a collision
no
a smaller force applied __ could have the exact same effect on motion as a much smaller force applied over a __ time
quickly, longer
any object at __ respect to a frame of reference, regardless of its ___, has a momentum of ___ with respect to that frame of reference
rest, mass, zero
Hitting a Haystack: the ______ force is applied over a long period of time so the force can be ______. Hitting the Brick Wall: the car is brought to a stop in a very ______ period of time so the force has to be much ________.
stopping, smaller, short, larger
what must change during a change in momentum- increasing momentum and decreasing momentum
velocity increase= positive force, decrease= apply negative force
how does conservation of momentum apply to collisions
when a system of objects collide in the absence of an external net force the net momentum of the system before the collision equals the net momentum of the system after the collision
when are impulses greater
when an object bounces- it has double impulse, momentum, and change in velocity if bounces bak to it's own height
When your on a skateboard Do you experience an impulse when you catch a ball of the same speed?
yes
When your on a skateboard When you throw a ball, do you experience an impulse?
yes
when your on a skateboard Do you experience an impulse when you catch it and throw it out again? Which impulse is greatest?
yes, catching and throwing it again is greater
What is the explosion formula?
(m1+m2)v1=m1v1f+m2v2f
If an eagle and a bumble are traveling at 10 km/hr which has the greater momentum? a. eagle b. bumblebee c. both
A (eagle has greater mass)
Which was more momentum: a 5 kg fish swimming at 100 m/hr or a 25 kg fish at rest? a. 5 kg fish b. 25 kg fish c.Both
A (fish at rest as no velocity)
