Chapter 8 : Momentum, Impulse, Collision
CHEE ZI QING A20SC0043
Momentum and Its Relation to Force
Conservation of mementum
Collisions and impulse
Conservation of Energy and Momentum in Collisions
Elastic Collisions in One Dimension
Inelastic Collisions
Collisions in Two or Three Dimensions
Centre of Mass(CM)
System of Variable; Mass: Rocket Propulsion
Centre of Mass and Translational Motion
Momentum = vector (direction+magnitude)
momentum,p= mv (mass x velocity)
unit : kgm/s
rate of change of momentum dp/dt = F
total momentum for a closed/isolated system remains constant unless there exists a net external force acting on it.
no force = no change in momentum = dp/dt=0
m1u1 + m2u2 = m1v1 + m2v2
change in linear momentum = impulse,J
p = mv = m(v-u) = Ft
the variation of F over time 
momentum is conserved
( elastic + inelastic collision )
momentum is conserved, m1u1 + m2u2 = m1v1 + m2v2
kinetic energy is conserved, u1+v1 = u2+v2
two object sticks together after collision
loss energy to thermal / potential energy
momentum is conserved, m1u1 + m2u2 = m1v1 + m2v2
gain energy during explosions
x-component
y-component
kinetic energy equation
Center of mass(CG) is a point at which the total mass of the body is assumed to be concentrated
(x,y) = ( Mx/M , My/M )
The center of gravity (CG) of an object is the point at which weight is evenly dispersed and all sides are in balance
translational motion of a rigid body as if it is a point particle with mass m located at COM
Rotation of the particle, with respect to the COM, is described independently
Fext = dp/dt = d(mv)/dt = M(dv/dt)-(u-v)dM/dt