Physics Topic A

velocity

rate of change of position (displacement/time)

speed

distance traveled per unit time (distance/time)

acceleration

the rate of change in velocity (change of velocity/time)

horizontal component of projectile motion (velocity)

velocity= v cos(x)

vertical component of projectile motion (velocity)

velocity= v sin (x)

newtons first law of motion

A body will remain at rest or moving with constant velocity unless acted upon by an unbalanced force

normal reaction force

the force perpendicular to the surface

gravitational force (weight)

the unbalanced force exerted on an object due to gravity

unbalanced force

the force acting on an object is not equal in size as and opposite in direction, leading to a change in the objects motion

electric force

a force which acts on charged particles

magnetic force

a force that acts on moving charged particles and magnetic materials

static friction

a force that stops the relative motion between two toughing surfaces

dynamic friction

a force that opposes the motion of two forces which are already sliding past each other

air resistance

a force that opposes the motion of a body through the air (fluid resistance or drag)

buoyancy

a force experienced by a body totally or partially immersed in a fluid (liquid or gas)

terminal velocity

the constant speed that a freely falling body eventually reaches when the force of gravity is balanced by the drag force (maximum speed)

elastic restoring force (Fh)

a force exerted by a material when it is stretched/compressed and tries to return to its original state

momentum

the product of mass and velocity (vector)

impulse

is the change in momentum (vector)

newtons second law (complicated)

The rate of change of momentum of a body is directly proportional to the unbalanced force acting on that body and takes place in same direction

newtons second law of motion (simplified)

the acceleration of a body is proportional to the force applied and inversely proportional to its mass (F= m a)

newtons third law of motion

If a body exerts a force on body B, then body B will exert an equal and opposite force on body A

the law of conversation of momentum

for a system of isolated bodies, the total momentum is always the same

angular displacement, radian

change in the angle of an object as it rotates around a fixed point or axis (vector)

angular velocity

the angel swept out by per unit time

frequency

the number of complete revolutions per unit time

centripetal acceleration

acceleration perpendicular to the velocity

centripetal force

the resultant force acting towards the center

work

the amount od energy transferred when an external force moves an object over an displacement

energy

the quantity that enables body A to do work on body B

kinetic energy

a body is able to do work due to its motion

potential energy

a body is able to do work due to its position

elastic collision

momentum and kinetic energy is conserved

inelastic collision

momentum is conserved but kinetic energy is not conserved

the law of conservation of energy

energy can neither be created nor destroyed; it can only be transferred from one store to another

fuels

a substance that can be made to react with other substances in order to transfer thermal energy or mechanical energy that can be used to do work

totally inelastic collision

momentum is conserved but kinetic energy is not and two bodies stick together

explosions

an inelastic collision, where momentum is conserved but kinetic energy is not

power

work done per unit time/ rate at which energy is transferred

efficiency

the quantity that gives a sense of proportion of input energy that is transferred to useful stores (usefull work/ total work or useful power/total power)