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Mechanics formulae

The 9 results the mechanics notes display, each with the conditions it needs to be true and a link to the lesson that states it. Of the 9, the formulae booklet prints 3, 4 are yours to memorise and 2 are working lines the notes derive in front of you.

Years 12-13 · 6 lessons with formulae.

A result the Edexcel formulae booklet prints is marked as such; one it does not print is marked to learn; and a result badged derived in the lesson is a working line the notes build in front of you rather than a standard result to memorise.

6 lessons

Kinematics with constant acceleration

v = u + at, \qquad s = \frac{(u + v)}{2}t

IN THE FORMULAE BOOKLETConditionsConstant acceleration in a straight line.

s = ut + \frac{1}{2}at^{2}, \qquad v^{2} = u^{2} + 2as

IN THE FORMULAE BOOKLETConditionsConstant acceleration in a straight line.

s = vt - \frac{1}{2}at^{2}

IN THE FORMULAE BOOKLETConditionsConstant acceleration in a straight line.

Kinematics with variable acceleration

v = \frac{dx}{dt}, \qquad a = \frac{dv}{dt}

NOT IN THE BOOKLET: LEARN ITConditionsMotion along a straight line, with x and v differentiable in t.

Forces and Newton's laws

F = ma

NOT IN THE BOOKLET: LEARN ITConditionsConstant mass, F the resultant force, measured in an inertial frame and in consistent units.

Projectiles

y = x \tan θ - \frac{gx^{2}}{2u^{2}\cos^{2} θ}

NOT IN THE BOOKLET: DERIVED IN THE LESSONConditionsLaunch at angle θ with speed u from the origin, no air resistance, constant g, and the projectile treated as a particle.

Friction and inclined planes

F ≤ μR

NOT IN THE BOOKLET: LEARN ITConditionsR the normal reaction. Equality holds only on the point of slipping or while sliding.

|m_Bg-m_Ag\sin\theta|\le \mu m_Ag\cos\theta

NOT IN THE BOOKLET: DERIVED IN THE LESSONConditionsA particle on a rough plane inclined at θ, connected over a smooth pulley to a hanging mass, both at rest. μ is the coefficient of static friction and the string is light and inextensible. The test decides only whether rest is possible; it does not give the direction of motion when it fails.

Moments

\text{moment} = \text{force} × \text{perpendicular distance}

NOT IN THE BOOKLET: LEARN ITConditionsDistance measured perpendicular from the pivot to the line of action of the force.

Every formula in the library is indexed by unit on the equation index, and the mechanics notes are where these results are derived and used. The 4 the booklet does not print are on the list of every formula to memorise, alongside the rest of the course.

Also: Statistics formulae · Further proof formulae