Mechanics (Momentum & Impulse)

Question 1

Define “Momentum”

Answer 1

Momentum (p) = Inertia in motion (inertia = object’s resistance to a change in motion)

• the product of Mass and Velocity of an object
• Measured in (Kg)(ms^-1)
• Vector Quantity

Question 2

Define “Impulse”

Answer 2

Change in momentum

Question 3

What is the Law of Conservation of Momentum?

Answer 3

In a closed system, if the net external force acting on the system is zero, momentum is conserved

Question 4

What is an Elastic Collision?

Answer 4

When total Kinetic Energy before and after a collision is the same (energy is conserved)
*two objects are NOT stuck together
to calculate:

(m1)(v1) + (m2)(v2) = (m1)(v’1) + (m2)(v’2)

v’ = velocity after collision

Question 5

What is an Inelastic Collision?

Answer 5

When total Kinetic Energy before and after a collision is different (energy is NOT conserved)
*two objects ARE stuck together
* loss of kinetic energy is MAX
to calculate:

m(1)v(1) + m(2)v(2) = [(m1) + (m2)]*v3

v3= combined velocity of stuck objects (after collision)