Unit 8
Momentum
Conservation of Momentum illustrated by a collision of two objects
Conservation of Momentum illustrated by a cannon and projectile
Lecture outline
Momentum is "mass x velocity" (p = mv).
Thus, it can be thought of as "mass in motion".
We use the letter "p", because the Latin word 'petere' means "to go to", "to attack". It's where we get the words "impetuous, petulant, and impetus"
"Impulse" is a concept Newton came up with to figure out his 2nd Law of Motion. We normally write the 2nd Law as "F=ma", but Newton originally expressed it using impulse.
Impulse is "change in momentum". Thus...
Collisions
In an "elastic" collision (billiard balls), both Kinetic Energy and momentum are conserved.
In an "inelastic" collision (billiard balls with Velcro), only momentum is conserved.
In an "elastic" collision (billiard balls), both Kinetic Energy and momentum are conserved.
In an "inelastic" collision (billiard balls with Velcro), only momentum is conserved.
Reading
BJU book: Ch. 11
Apologia book: Ch. 9
Lab
"Collision Lab"
Homework
BJU book: Ch. 11
Apologia book: Ch. 9
Lab
"Collision Lab"
Homework
| 8.linear_momentum_homework__problems.docx |