Term
linear momentum of an object is defined as 

Definition
The linear momentum 'p' of an object :
is the product of its mass & a velocity
ex. a faster & heavy truck has MORE momentum than a small moving car
aka it takes MORE force to stop the truck than the car. 


Term

Definition
→ →
p = m v
where :
p : momentum (a vector)
v: velocity (m/s)
m: mass (kg) 


Term
Momentum is a vector and points in the _____ direction as the _______ vector. 

Definition


Term
One can also say that the momentum vector is _______ to the velocity vector,
if the momentum vector ______ if the velocity vector doubles. 

Definition
directly proportional, doubles 


Term
A _____ is required to increase, decrease, or change the direction of momentum 

Definition


Term
relate momnetum to Newton's second law 

Definition
the rate of change of momnetum of an object is equal to the net force applied to it. 


Term
Give equation that relates momentum to Newton's second law 

Definition
ΣF=Δp/Δt
sum of forces= change in mommentum/change in time
same as
ΣF=p final  p inital/Δt
same as
ΣF=mv2 mv1/Δt 


Term
Momentum is a ______ quality 

Definition
conserved,
momentum is same before and after a collsion etc..
'the total momemtum of an isolated system of objects remains CONSTANT 


Term
Equation for conservation of momentum (such as 2 objects colliding) 

Definition
m_{A }v_{A } + m_{B }v_{B} _{= }m_{A }v_{A } + m_{B }v_{B} 


Term
In a given system, momentum will always be conserved if _____ 

Definition
no external forces are present
ex. friction, gravity 


Term
Conceptual Example 75:
An empty sled is sliding on frictionless ice when Riley drops vertically from a tree above onto the sled. When she lands, does the sled speed up, slow down, or keep same speed?
B. What happens if Riley falls sideways off the slide? 

Definition
A. Speed decreases
fall vertically: no inital horizontal momentum, so the total horizontal momentum is equal to the momentum of sled intinally.
b/c sled has more mass, the speed decreases
B. SAME speed b/c momentum is conserved 


Term

Definition
impulse (Δp) =
force • Δt
unit: Newtons/ seconds 


Term

Definition
is equal to the total change in momentum 


Term
a collision in which the total kinetic energy is called an 

Definition
elastic collision
KEf= KEi 


Term
give equation for a totally elastic collision 

Definition
1/2m_{1}v_{1}+1/2m_{2}v_{2}=1/2m_{1}v'_{1 + }1/2 m_{2}v'_{2}
where v' is velocity after collision
(recall ke is 1/2 mv) 


Term
Give equation for v'1 in elastic collision 

Definition
v'1 = (m1m2/ m1 + m2) x V1 


Term
collisions in which kinetic energy is NOT conserved is called? 

Definition


Term
In a totally elastic collision what happens to the objects 

Definition
they collide & go off in seperate directions 


Term
In a totally inelastic collision what happens to the objects 

Definition


Term
 In a totally inelastic collision what is conserved?


Definition
momentum & ofcourse TOTAL energy as always
*energy not created or destroyed 


Term
Give equation for inelastic collision 

Definition


Term
Give components of theta for:
x axis
y axis
flat & incline 

Definition
FLAT
X: cosθ
y: sinθ
INCLINE
X:sinθ
Y:cosθ 

