Unit 3 - Impacts and Linear Momentum Flashcards
Momentum is
A measurement of how much mass is in motion
Equation for momentum
P = mv
Momentum = mass X velocity
What is another way in which the equation for mmoementum can be written
Delta P = F X delta T
what type of quantity is momentum
What does this mean
Vector
Has direction as well as magnitude
What is impulse
The overall effect of a force acting over time
What is the equation of impulse
Impulse (J) = Force X change in time
J = F X delta t
Momentum is ___________ and as are __________ and ____________
Conserved
Energy and angular momentum
For a collision wheere objects will be moving in 2 dimensions the momentum will be conserved …..
In each direction independently
Momentum before =
Momentum after
What is an elastic collision
Where there is no net loss in kinetic energy in the system as a result of the collision
What is the result of the following collision?
A colides with an equal mass of B which is at rest
A comes to dead stop
B gains exact speed as A had before
What is the result of the following collision?
A collides with equal mass B (both moving towards each other)
Objects have equal but oppositely directed velocity
Two objects bounce off each other exchanging velocity
What is the result of the following collision?
Heavy object A collides with a much lighter object B
Final velocity of the heavy object tends to its initial velocity
Light object has little effect on the heavier one
The velocity of the heavy object tends to double to initial velocity of the light object
What is the result of the following collision?
A light object collides with a much heavier object which is at rest
The light object bounces off the heavier object maintaining the same speed but with opposite direction
What is the equation that allows the velocity of object B to be determined in the case of a HEAD OF ELASTIC COLLISION
Vb = (2ma / ma + mb) Va
What is the hallmark of an inelastic collision
Kinetic energy is not conserved
What is a reason why kinetic energy may not be conserved
Transformed to another form of energy
What is the coefficient of restitution
A number between 0 and 1 which describes how elastic or inelastic a colision is
A coefficient of restitution of 0 would mean
The collision is perfectly inelastic
A coefficient of restitution of 1 would mean
The collision is perfectly elastic
What is the centre of mass
Average position of all parts of a system weighted according to their masses
Position at which the weighted position vectors of all the parts of a system sum to 0
Describe the equation for finding the COM along the X axis
COMx = (m1.x1)+(m2.x2)+(m3.x3)
__________________
m1 +m2 +m3
Centre of mass AKA
Centre of gravity
If the centre of mass lies outside of the base of an object what is the effect of this
The object would tip
