Circular Motion and Oscillations

Useful information

• Link to specification. http://www.ocr.org.uk/images/81024-specification.pdf

• Data, Formulae and relationships booklet. http://www.ocr.org.uk/images/70733-datasheet-data-formulae-and-relationships-specimen.pdf

• Past papers, mark schemes and examiners reports here. http://www.ocr.org.uk/qualifications/as-a-level-gce-physics-a-h158-h558/

Useful Simulations (courtesy of PHET)

• Gravity and orbits. http://phet.colorado.edu/en/simulation/gravity-and-orbits

• My Solar System. http://phet.colorado.edu/en/simulation/my-solar-system

• Lady Bug Motion – 2D. http://phet.colorado.edu/en/simulation/ladybug-motion-2d

Circular Motion

Define the Radian

Angle Conversions

• How do you convert angles from degrees into radians?

• How do you convert from radians into degrees?

A force perpendicular to the velocity of an object will make the object describe a circular path

Centripetal Force and Acceleration

•What is meant by centripetal force? •What is meant by centripetal acceleration?

Key Equations

• What equation can be used to calculate the tangential velocity of an object describing a circle? Express in terms of r and T.

• What equation can be used to calculate the centripetal acceleration of an object describing a circle? Express in terms of a, v and r.

Centripetal Force Equation

Gravitational Fields

How does a mass create a gravitational field around it?

Gravitational Fields Lines

• What are the features of gravitational fields lines?

• How can they be used to indicate the strength of a gravitational field?

Radial and Uniform Fields

• What is the difference between a radial and a uniform field?

What is the definition of gravitational fields strength?

Newton’s Law of Gravitation

How could this law be put into words?

What does this equation calculate?

•g=-GM/r2

• How can this equation be used to calculate the mass of the Earth or similar object?

You need to be able to..........

• Analyse circular orbits in an inverse square law field by relating the gravitational force to the centripetal acceleration

What is the period of a circle?

Can you derive this equation?

What is Kepler’s third law?

What do each of these terms mean?

What is the definition of geostationary satellite?

Can you give some uses of geostationary satellites?

• Some hints here: http://www.ehow.com/list_7218182_uses-geostationary-orbit-satellites.html

Have a look at this

• Real time satellite tracking http://www.n2yo.com/satellites/?c=34