physics
what does it mean when something is scalar?
when something has a magnitude but no direction
what does it mean when something is vector
vector means when something has both a magnitude and direction
give three examples of scalar
speed, mass, distance
volume, power pressure
give three examples of vector
velocity, force, weight
Explain distance
distance is the length of a path between two points
Explain displacement
displacement is the direction from the starting point and the length of a straight line from the starting point to the ending point
What is newtons third law?
when two objects interact with each other, they exert equal and opposite forces on each other.
What is the centre of mass
the centre of mass of an object is the point at which its mass can be thought of as being concentrated
What is Suspended Equilibrium
the centre of mass directly below the point where it is suspended
what is resultant force
resultant force is the result of all forces acting (overall force)
what does zero resultant force mean
if an object is not movingand has zero resultant force it stays not moving. whereas if an object is moving and has zero resultant force it means it is moving at a steady or constant speed.
what is the equation for weight
weight=mass x gravitational field strength (w=m x g)
what is weight
the weight of an object is the force of gravity that acts on its mass
what is gravitational field strength
gravitational field strength is an accelleration due to the strength of the gravitational field
what is work in physics
work in physics is the amoubt of energy transformed (changed) when a force moves (in the direction of the force)
what is the equation for work done
work done = force x distance
what is the equation for joules
joules = newtons x metres
what is the eqution for power (work done)
power = work done / time
what is the equation for watts
watts = joules / seconds
what is hookes law
hookes law states that the force applied to an elsastic object (spring) is directly proportional to the extension it causes
what is elasticity
the ability to be deformed by forces but still return to its original shape and size
what is plasticity
when an object is deformed by forces but does not return to its original shape and size when forces are removed
what is extension
extension is the distance an object has been stretched or extended by, NOT how long it is. for example an unstretched spring is 2cm and is stretched so it is now 10cm ling so the extension is 8cm long
what is the eqution for force (springs)
force = spring constant x extension
what is the equation for kinetic energy
kinetic energy = 1/2 x mass x velocity ^2
what is the equation for density
density = mass x volume
what is the equation for gravitational potential energy
gravitational potential energy = gravitational field strength x height x mass
what is elastic potential energy
elastic potential energy is the energy being stored by an elastic object when it is being stretched or squashed
when will an object store Ee
when an object is being stretched, the more Ee it has but if an object is not stretched then it is not storing any elastic potential energy
what is the equation for power (energy)
power= energy / time
what is the difference between contract and non contract forces
contact forces are forces that occur due to objects being in contact with each other. whereas non contact forces don't need to be in contact with another object.
explain energy
energy cannot be created or destroyed, only transferred
name examples of contact forces
friction, air resistance, push, pull
name exaples of non contact forces
gravity, magnetic, electrostatic