combination Flashcards
acceleration formula
change in velocity/time
gravitational field formula
W/m
resultant force
sum of total forces acting on an object
Newtons 1st law
an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant force
springs constant formula
force per unit extension k=F/x
limit of proportionality
the extension that Hookes law no longer applies to - the extension is no longer proportional to the force
formula of force in relation to mass and acceleration
force = mass x acceleration
describe an object in circular motion
- speed increases as force increases, with mass and radius constant
- radius decreases if force increases, with mass and speed constant
- an increased mass requires an increased force to maintain radius and speed
friction
force that opposes motion and causes heating when two objects are rubbed against each other
moment of a force
measure of its turning effect
when is an object in equilibrium
when the sum of all forces must be zero, when anticlockwise moments = clockwise moments
torque/turning effect
a measure of the force that can cause an object to rotate about an axis
centre of gravity
a point where the mass of the body is concentrated
5 examples of energy stores
kinetic, GPE, chemcial, elastic, electrostatic
how is energy transferred during events and processes (4 examples)
forces, electrical currents, heating, waves
conduction
transfer of thermal energy by collisions of particles from hot regions to cold regions
experiment to test conduction
the boiling water wax experiment thing
why are metals good conductors
metals contain free electrons that can move anywhere in the lattice. these electrons gain heat energy in the hot regions and carries the energy to other parts of the lattice.
convection
hot fluid particles expand and rise, whereas cold fluid particles shrink and sink.
infrared radiation
transfer of thermal energy without a medium
conservation of energy
energy can neither be created nor destroyed
kinetic energy formula
1/2mv^2
gravitational potential energy formula
m x g x h
mechanical work done
the amount of force needed to move an object a certain distance
what mechanical work done formula
W = Fd
efficiency formula
useful energy ouput/total energy input x 100
or
useful power input/total power input x 100
power
the rate of transfer of energy, P = W/t, P = ΔE/t
pressure
force per unit area, P = F/A
mechanical work done
force to move an object
