Term 2 Week 6 2017

Homework

• Ex 2A, p.19-22, Working with Errors
• Ex 2B, p. 26-37 Data Processing & Errors
• Ex 4H, p. 160-162, Rotational Motion
• Ex 4I, p. 167-171, Angular Momentum

Rotational Momentum (Angular Momentum)

For a point mass L = Pr

Linear Momentum times the radius distance between the point mass and the axis of rotation

Momentum: Rotational Linear

Equation: L = I⍵ P = mv

Units: kgm2s-1  kgms-1

• Rotational Momentum and Linear Momentum have different units so they cannot be equated with each other and are independent of each other.
• Rotational Momentum obeys the same law of conservation that Linear Momentum obeys. In the absence of outside forces, total momentum is always conserved.

Conservation of Angular Momentum in the ISS

Mechanics 2015 Question 3 on Cats & Gravity (Conservation of Angular Momnetum L=Iω) 

Examination Paper 2015  AS 91524

Assessment Scedule 2015 AS 91524

Precession

Egg Spinning

Rotational Kinetic Energy

Energy: Rotational Linear

Equation: Ek(rot) = ½I⍵2 Ek(lin) = ½mv2

Units: Joule Joule

• Rotational Kinetic Energy and Linear Kinetic Energy have the same unit so they can be equated with each other and are interdependent on each other.
• The law of conservation of total energy can be applied with all types of energy. You will be using mostly gravitational potential, linear kinetic, and rotational kinetic energies.

• Total Kinetic Energy = Ek(rot) + Ek(lin)

= (½I⍵2) + (½mv2 )