forces and motion and energy Flashcards
(24 cards)
what is hooke’s law
the extension of a spring is directly proportional to the force applied
what does directly proportional mean
straight line through the origin
what is elastic behaviour
spring will return to its original length when force is removed
what is plastic behaviour
will not return to its original length when force is removed
so is DEFORMED
as a rocket increases in height what happens to energy store
gravitational energy store increases
what is energy
the ability to do work
laws of conservation of energy
energy cannot be created or destroyed
can only be transferred from one type to another
what are the 9 types of energy
kinetic
thermal
nuclear
gravitation potential
chemical
elastic potential
light
sound
electrical
what are the 4 ways energy can be transferred
electrically
mechanically
by radiation
by heating
how can energy be transferred electrically
in the current
flows through
how can energy be transferred mechanically
by movement
by collisions
how can energy be transferred by radiation
electromagnetic waves
how can energy be transferred by heating
conduction
convection
what is a scalar quantity and what are some examples?
has magnitude only
eg speed and distance
what is a vector quantity and what are some examples
has magnitude and direction
eg velocity , acceleration and force
what unit is distance always in
metres
what unit is time always in
seconds
what unit is velocity always in
m/s
what unit is acceleration always in
m/s squared
what unit is mass always in
kg
what happens when an object falls
Initially accelerates due to gravity
Air resistance increases as speed increases
Eventually reaches terminal velocity when forces balance
what is Newton’s first law
An object will remain at rest or in uniform motion unless acted on by a resultant force.
what is newton’s second law
Force = mass x acceleration
The acceleration of an object is directly proportional to the resultant force acting on it and inversley proportional to its mass.
eg more force = more acceleration
if object is heavier accelerates less
what is Newton’s 3rd law
For every action, there is an equal and opposite reaction.
