forces of balance Flashcards
what do vectors have
magnitude and direction
what do scalars have
only magnitude
name some examples of vectors
accelleration, velocity, force, momentum, displacement
name some scalars
speed
energy
distance
mass
time
temperature
name some contact forces
tension, friction, air resistance, normal force
name some non contact forces
gravitational force
electrostatic force
magnetic force of attraction or repulsion
what is a force
a push or pull acting on an object due to interaction with another object
what is an interaction pair/ Newton’s 3rd law
When 2 objectst interact the force they exert on eachother are equel yet opposite
sun and earths example of interaction pair? look in cgp pg 51 if help
This is an example of Gravitational force
The sun and the earth are attracted to each other. They share an equal force but an opposite force of attraction which is felt by both the sun and earth.
what is centre of mass
the point on the object at which it will balance and exert a force-
AQA definition - the point at which the weight of the object is considered to be acting
what can weight be measured with
calibrated spring balance / newton meter
what is the unit of force
newtons [N]
what are directly proportional
mass and weight
what is weight
The force acting on an object due to gravity
what may change gravitational force/ weight
different locations
what is equation for weight
weight = mass x gravitational field strength
what is resultant force
overall force acting on an object
what is altitude
height of object or point in relation to ground or sea level
what Is thrust
forward force
what is velocity
the speed of which something is moving in a direction towards something
what is displacement
change in position of an object
what does the length of arrow and arrow direction show.
length shows the size/magnitude of force
arrow shows the direction of force
what doe a free body diagram show
all the forces acting on an object
what is lift/ drag
a force acting in the oposite direction to the motion
what does it mean for the object to be I equilibrium
if the forces on it are balanced / equal zero
properties of an elastic material
The elastic material will always return bc to its original shaper size once the forces have been removed.
what ways do forces on elastics act
the forces on an elastic have same magnitude yet opposite direction
what does elastic deformation mean
elastics can be stretched, squeezed/ compressed or bended. This Is called elastic deformation however they will always return back to normal after forces removed
non elastic materials will not go back to their original size or shape once being compressed, stretches or bended.
what are examples of inelastic material
polymers - plastics
what are examples of elastic materials
rubber glove
rubber band
tennis ball
eraser
spring
what is inelastic deformation
when an inelastic material changes shape or size after being stretched, compressed or bended by the forces acting on it, once the forces are removed the material will not return to its previous shape or size
when we are deforming elastic material we are exerting a force to do work on the elastic material
work done is = to elastic potential energy
when we are doing work on a elastic material we are transferring energy into an elastic potential energy. if it is elastically deformed all this energy is transferred into elastic potential energy store.
why do you need more than 1 force to deform elastic material
if elastic material only had one force acting on it, it would move in a direction it would not compress, strep h or bend (change shape ) there has to be more that one force in opposite directions acting upon the elastic material
what is directly proportional in elasticity
extension is directly proportional to force
what is limit of proportionality in extension and force
eventually there will be a maximum force bing exerted in the elastic material. as a result the elastic material would’ve reaches its maximum extension extension will no longer be proportional to force.
this can be shown on a force and extension graph - the line would be in direct proportion but then flatten but
what is work
when force is applied to an object/ body causing that object to be displaced/ moved
a force does work on an object when that object is then displaced.
what is momentum
strength or force gained by motion or by a series of events
what is motion
change in position of an object overtime
what is velocity
how fast and object is moving in a direction
what is speed
how fast/ rate at which and object is moving
what is acceleration
rate of change of velocity
what is displacement
change in position of the object
what is newtons 2nd law
the acceleration of an object is proportionally to the resultant force applied. - The larger the resultant force acting on an object the more the object accelerates.
the acceleration of an object is inversely proportional to the mass of the object ( as mass of the object increases acceleration will decrease [ they act in the opposite nature])
describe the acceleration practical
what is control variable - mass of the car
what is the independent variable- the mass attached to the end of the string
what is the dependant variable- acceleration of the car
what is newton 1st law (inertia)
a resultant force is needed to make something start moving, speed up or slow down. An object that is stationary will remain stationary and an object that is moving will remain moving if the resultant force is balanced/ 0
what is the force in acceleration practical
weight of the mass applied at the end of the string
how can we also experiment how varying the mass of the object affects acceleration produced by a constant force.
what is the hypothesis
force is constant/ we keep the mass applied to the end of the string the same. we add a weight to the car eg 200g and measure the acceleration now. we continue to increase the mass added to the car.
as we increase the mass of the car the acceleration will decrease.
what causes the velocity of an object to change.
velocity will only change if there is a non zero resultant force acting on it.
what will produce acceleration an what are the five different forms can acceleration take up.
a non 0, unbalanced resultant force. starting, stopping, speeding up, slowing down, changing direction
what does it mean if objects/ forces are in equilibrium
The resultant force is 0
what causes a force on earth
The force of gravity close to the earth is due to the gravitational field around the earth
what does weight depend on
the weight of an object depends on the gravitational field strength at the point where the object is.
example
Gravitational field strength (g) is measured in newtons per kilogram (N/kg). The Earth’s gravitational field strength is 9.8 N/kg. This means that for each kg of mass, an object will experience 9.8 N of force. Where there is a weaker gravitational field, the weight of an object is smaller.
what is work measured in
joules ( J )
work ///capacity///?
One joule of work is done when a force of one newton causes a displacement of one metre.
1 joule = 1 newton meter
what forces are involved in the compression, stretching and bending of a material
push and pull forces
what is spring constant and what is it measured in
spring constant tells how stiff a spring is and is measures in newtons per meter
what store does compressing or stretching (extension) do work in ?
a force that stretches or compressed a spring does work, and elastic potential energy is stored in the string.
what is a linear relationship between force and extension
forces id directly proportional to extensions
what is a non linear relationship between force and extension?
does not obey Hookes law there for force is not directly proportional to Hookes law
what equation if used to work out work done in stretching or compressing a spring
elastic potential energy= 0.5 x spring constant x extension [squared]
