A-Level Physics: Mechanics: Overview

when an object is moving at uniform acceleration

9.81ms^-1

scalar quantity which describes the amount of ground an object has covered

overall distance travelled from starting position

scalar quantity describing distance travelled per unit time

rate of change of displacement

rate of change of velocity

where the acceleration of an object is constant

change in velocity over time

change in velocity

change in velocity over time

acceleration

displacement

change in displacement over time

velocity

velocity of an object at a specific point in time

by drawing a tangent to the graph at a specific point in time and calculating the gradient

displacement-time graph

velocity of an object over a specified time frame

by dividing final displacement by time taken

quantities describing only the magnitude, and not direction

quantities describing both magnitude and direction

distance, speed, mass, temperature

displacement, velocity, force, weight, acceleration

through absolute direction (north, east), a relative direction (left, right) or by the angle made with the horizontal

where a vector is split into two parts which are perpendicular to each other

calculation and scale diagram

by the formulas x = V cos theta, y = V sin theta

choose an appropriate scale and make note of it by the diagram, use a ruler and protractor to draw the vector as described in the question. draw the vector’s horizontal ad vertical components, making sure they meet in a right angled triangle, then measure the value of the vectors using initial scale

calculation and scale drawing

when the two vectors are perpendicular to each other

when the angle is something other than 90

the components are independent of each other, so they are evaluated sepetarely

when the acceleration is constant

a diagram which shows all the forces that act on an object

each of the forces acting on the object and how they compare with each other depending on magnitude

when object at rest will remain at rest, an object traveling at a constant velocity will remain at a constant velocity

the acceleration of an object is proportional to the resultant force experienced by an object (F=ma)

resultant force, mass or acceleration (if two of the others are known)

the mass of the object must be constant

by substituting a resultant force of 0N, which gives an acceleration of 0ms^-2

where frictional forces acting on an object and driving forces are equal

there is no resultant force and so no acceleration so the object moves at a constant velocity

as a skydiver leaves the plane they accelerate because their weight is greater than the air resistance acting on them. as their speed increases the magnitude of air resistance also increases, until the weight and air resistance become equal

force per unit mass exerted by a gravitational field on an object

g=F/m

gravitational force that acts on an object due to its mass

by multiplying the object’s mass by the gravitational field strength

mass x gravity

for each force experienced by an object, the object exerts an equal and opposite force

product of mass and velocity of an object

mass x velocity

momentum is always conserved in an interaction where no external forces act

no external forces act

force multiplied by the perpendicular distance from the line of action to the force to the point

force x perpendicular distance

for an object in equilibrium, the sum of anticlockwise moments about a pivot is equal to the sum of clockwise moments

the point at which gravity appears to act

exactly at the object’s centre

force causing a motion multiplied by the distance travelled in the direction of the motion

force x distance in direction of motion

energy an object has due to its motion

w