AQA Mechanics 2

 

 

 Moments and Centre of Mass

Finding the moment of a force about a given point.

Knowledge that when a rigid body is in equilibrium, the resultant
force and the resultant moment are both zero.

Determining the forces acting on a rigid body when in equilibrium.

 

This will include situations where all the forces are parallel, as on a
horizontal beam or where the forces act in two dimensions, as on a
ladder leaning against a wall

Finding centres of mass by symmetry (e.g. for circle, rectangle).

 

Finding the centre of mass of a system of particles.

 

Finding the centre of mass of a composite body.

 

Finding the position of a body when suspended from a given point and in equilibrium

 

 Kinematics

Relationship between position, velocity and
acceleration in one, two or three dimensions, involving variable acceleration.

Application of calculus techniques will be required to solve problems

 

Finding position, velocity and acceleration vectors, by differentiation or integration.

 

 Newton's Laws of Motion

Application of Newton's laws to situations, with variable acceleration.

Problems will be posed in one, two or three dimensions and may
require the use of integration or differentiation.

 Application of Differential Equations

One-dimensional problems where simple differential equations are formed as a result of the application of Newton's second law

 

 Uniform Circular Motion - Khan Academy Videos

Motion of a particle in a circle with constant speed.

 Problems will involve either horizontal circles or situations, such as a
satellite describing a circular orbit, where the gravitational force is
towards the centre of the circle.

Knowledge and use of the relationships

 

Angular speed in radians s-1 converted from other units such as revolutions per minute or time for one
revolution.
Use of the term angular speed.
Position, velocity and acceleration vectors in relation to circular motion in terms of i and j. Candidates may be required to show that motion is circular by
showing that the body is at a constant distance from a given point

Conical pendulum.

 

 Work and Energy - Khan Academy Videos

Work done by a constant force.

Forces may or may not act in the direction of motion.
Work done = Fd cosθ

Gravitational potential energy.

Universal law of gravitation will not be required.

Gravitational Potential Energy = mgh

Kinetic energy.

Kinetic Energy 1/2mv2

The work-energy principle.

Use of Work Done = Change in Kinetic Energy.

Conservation of mechanical energy.

Solution of problems using conservation of energy.
One-dimensional problems only for variable forces.

Work done by a variable force.

Use of ∫ F dx will only be used for elastic strings and springs.

Hookes law.

 

Elastic potential energy for strings and springs.

Candidates will be expected to quote the formula for elastic potential
energy unless explicitly asked to derive it.

Power, as the rate at which a force does work, and the relationship P = Fv.

 

 Vertical Circular Motion - Khan Academy Videos

 Circular motion in a vertical
plane.

Includes conditions to complete vertical circles.