# A2 Physics

All the Topics in the A2 Physics Syllabus

- Created by: Billy Radford
- Created on: 13-12-10 18:44

First 376 words of the document:

Physics January Revision.

Topic 2, Further Mechanics.

Linear Momentum.

Momentum is equal to mass times velocity and therefore the units are kilogram seconds to the minus one

or Newton seconds.

Momentum is a vector because velocity is a vector.

The principle of conservation of linear momentum states that in any interaction between bodies, linear

momentum is conserved provided no external force acts on the bodies.

The rate of change of momentum of an object is directly proportional to the resultant force which acts on

the object. Force is equal to change in momentum divided by time. Although if mass is constant force is

equal to mass times acceleration.

Impulse is equal to change in momentum. Impulse is equal to force times change in time.

In momentum collisions in 2 dimensions the component of the momentum in the x direction is conserved

and the component in the y direction is conserved.

Momentum and energy.

Energy cannot be created or destroyed. Energy can be transferred from one form to another but the total

amount of energy in a closed system will not change.

Kinetic energy is equal to half times the mass times the velocity squared. Kinetic energy is also equal to

momentum squared divided by 2 times mass.

Elastic potential energy is equal to half times k times the change in x squared.

Gravitational potential energy is equal to mass times gravity times the change in height.

In elastic collisions kinetic energy is conserved and momentum is always conserved. In inelastic collisions

kinetic energy is not conserved but momentum is always conserved.

Motion in a circle.

One radian is equal to 57.3 degrees.

To convert degrees to radians you times by pie over 180.

To convert radians to degrees you divide by pie over 180.

Angular velocity is the same as angular frequency and angular speed.

Angular speed is equal to angle turned divided by time.

Angular speed is also equal to 2 pie over time for one rotation.

Angular speed is also equal to 2 pie times frequency.

Linear speed is equal to angular speeds times the radius of the circle.

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