AS1 1.7 Linear Momentum and Impulse Flashcards
Define momentum
Momentum is defined as the product of the mass and velocity of an object
What is the principle of momentum conservation?
In an isolated/closed system, the total momentum before the collision is equal to the total momentum after the collision
Conservation of momentum equation
(in an isolated system)
T momentum before = T momentum after
m(1)u(1) + m(2)u(2) = m(1)v(1) + m(2)v(2)
m = mass
u = initial velocity
v = final velocity
Momentum Equation
Momentum = mass x velocity
p = m x v
m = mass (kg)
p = momentum (kgms^-1)
v = velocity (ms^-1)
Momentum equation is the bodies coalesce (stick together) after impact
T momentum before = T momentum after
m(1)u(1) + m(2)u(2) = (m1 + m2) x v
Momentum equation in the explosive case (eg shooting a gun)
(direction is vital in momentum questions)
T momentum before = T momentum after
0 = m(1)v(1) + m(2)v(2)
Elastic Collisions
Collisions in which the Kinetic Energy is conserved
Inelastic Collisions
Collisions in which Kinetic Energy is not conserved
Totally Inelastic Collisions
Collisions in which the two objects stick together, with a large loss in Kinetic Energy
Is momentum conserved in collisions?
Momentum is always conserved, whether in an elastic or inelastic collision
Is Kinetic energy conserved in collisions?
It is only conserved in elastic collisions.
Is the Total energy conserved in collisions?
The total energy is conserved in all collisions.
Force/momentum equations
F = ∆p / t
F = p(final) - p(initial) / t
F = mv - mu / t
F = m(v - u) / t
Where,
∆p = change in momentum
p = momentum
m = mass
v = final velocity
u = initial velocity
t = time
F = Force
Newton’s second law in terms of momentum
The rate of change of momentum of a body is directly proportional to the applied force and acts in the direction of the force.
What is impulse?
Impulse is the product of the force and time the force is applied for.
Impulse equation.
Impulse = Ft = mv- mu
