dynamics Flashcards
what is speed ?
the distance travelled per unit of time
what is instantaneous speed ?
speed at one point in a journey
what is average speed ?
the total distance divided by the total time
what is acceleration ?
the change in velocity per second
is deceleration negative ?
yes
how can you calculate the distance for a journey ?
area under the line
when is a forces acting on an object balanced ?
when they are equal in size and act in opposite directions
do balanced forces cancel each other out ?
yes so the object will remain still
you need a direction when stating an unbalanced force. true or false ?
true
why do we want friction ?
why do we not want friction ?
to slow an object down
to enable an object to travel at greater speeds without wasting energy
what is newtons first law ?
BALANCED FORCE GIVES CONSTANT VELOCITY
an object will either remain at rest or continue to move with the same speed (balanced forces) and direction until acted on by an unbalanced force.
what is newtons second law ?
when an object is acted upon by an unbalanced force it will accelerate or decelerate.
what is mass ?
the quantity of matter in an object
what is weight ?
force of gravity on an object
what is gravitational field strength ?
the size of force per kilogram of mass
mass should be in grams true or false ?
false should ALWAYS BE IN KG
what is terminal velocity ?
weight is balanced by air friction
how do you get to terminal velocity ?
the weight downwards is greater than the air friction upwards so there is an unbalanced force downwards this means that the parachutist accelerates downwards.
as the speed increases the air friction increases until it balances the weight. the parachutist has then reached their maximum velocity and will then travel at a constant speed
what is Ew (work done) ?
pushing an object over a distance
what is Ep (gravitational potential energy)
how the work done in raising an object is stored
any object that is above the ground has gravitational potential energy, true or false ?
true
what is Ek (kinetic energy) ?
the energy associated with any moving object
what transition of energy is a falling object ?
potential energy to kinetic energy so Ep=Ek
what transition of energy is an object on a slope ?
potential energy to kinetic energy and heat (friction)
Ep=Ek+Ew (friction) Ep=Ek
what transition of energy is a pendulum ?
continual from potential energy to kinetic then back to potential
Ep (top) =Ek (bottom) = Ep (top)
