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forces and pressure forces (Anna) - Coggle Diagram
forces and pressure forces (Anna)
formulae
:
1.weight (N)=mass (kg) x g(gfs)
speed(m/s)=distance (m) x time (s)
moment (Nm) = force (N) x distance (m)
pressure(Pa)= force(N) over area(M2)
work done (J) =force(N) X distance (m)
density =mass over volume
difference between mass and weight
definition
SI unit
measuring tool
consistency
MASS
WEIGHT
weight is the amount of gravitational force acting on an object
N
spring balance
varies in different in diff ocations
force also measured by this
mass is the amount of substance in an object
kg
beam/electronic balance
remains unchanged
the larger the mass of an object the heavier its weight
sources of energy
renewable
biofuel energy
using ethanol from sugarcane :cry:CO2 still produced
CPE-heat-KE(vehicle
)
nuclear energy
using energy from nucleus of atom
a small amount of fuel can generate a large amount of electricity(a lot of heat)
heat-KE(turbine)-EE
wind energy
using wind to turn turbine: :crying_cat_face:birds are sometimes killed by turbine
KE-(wind)KE(turbine)-EE
hydroelectric energy
water flows through a dam,turbine inside the dam is turned . :cry:building a dam can cause flooding upstream
GPE-KE(water)-KE(turbine)-EE
solar energy
using solar energy :smiley:using solar panels . no pollutants,clean energy
light-EE
geothermal
water is heated up underground,steam used to turn turbine
heat-KE(steam)-KE(turbine)-EE
ALL TO GENERATE ELECTRICITY
gravitational potential energy,kinetic energy,chemical potential energy,electrical energy,thermal energy/heat,sound energy
non renewable
fossil fuel
disadvantages
produces CO2
greenhouse gas
worsen global warming
CPE-heat-KE-EE
ABOUT TRANSFER OF ENERGY
pressure
force over area
to find area :length x breath the object
to find force take the weight of the box X 10(the g)
then take those two and divide
the smaller the contact surface area the larger the pressure created
OR the heavier the object the larger force exerted ,creating a larger pressure
wearing snowshoes to move across snow depends on low pressure for its efficient function
E.G a sharp needle apply more pressure than a smooth one with the same force, because the it has lesser contact surface area
atmosphere pressure: air sucked out of straw
atmospheric pressure pushes drink downwards foring drink to go up and staw to go down
liquid pressure :less liquid pressure,less water on top
more water on top,experience more liquid pressure
e.g the further you go underwater, the more pressure there is
effects of forces
change state of motion
change direction of moving object
change speed of moving object
move stationary object/stop moving object
change size/shape of object
force is a push or a pull acting on an object
non-contact(non direct)
magnetic force
principle
like poles repel
unlike poles attract
force of attraction
force of repulsion
is a force of attraction between magnets and magnetic substances
useful e.g : the magnetic needle in a compass indicates the direction to help us navigate through jungles and oceans
gravitational force
gravity is a force that pulls . it acts between two masses without direct contact with each other
(gravitational force
)
gforce of earth pulls all objects towards its centre
the more mass an object has the stronger the gravitational force acting on it .hence the object weighs more
gravitational field strength(g) is the amount of gravitational force acting on a 1 kg mass
distance between two masses
distance between two masses
increases
, the force
decreases
mass of object: object larger mass has greater gravitational force
e.g earth
gforce
is
greater
than moon because
mass
of earth is
greater
weight (N)
mass(kg) x g(N/kg)
contact(direct)
fritional force
cons
:
objects used become worn out
wear and tear
waste energy
pros
overcome by:
ball bearings
lubricant oil
friction occurs when two objects are in physical contact with each other
it is a force that acts in the opposite direction and opposes the motion of an object
hence friction slows down or stops moving object :
greater when object moves on a rough surface than a smooth surface
produce a turning effect (moment)
PRINCIPLE OF MOMENT: at equilibrium (balanced state) , the sum of clockwise moment is EQUAL to the sum of anti-clockwise moment
plank is balanced because ACW moment and CW are equal.
DISADVANTAGE OF
FOSSIL FUEL
ADVANTAGE of NO
fossil fuel
it does not produce any greenhouse gases and will not contribute to global warming
it is a renewable source of energy that will not run out
fossil fuel is non renewable source of energy that it will eventually run out
burning fossil fuel produces carbon dioxide which a greenhouse gas(trap heat) than contribute to global warming
destructive forces of nature
many natural disasters exert a large amount of force on object and people,resulting in large scale destruction
volcanic eruption
tsunami
earthquakes
energy:is the ability to do work
joule(J)
also used to measure work done and heat
work done, a force must be acting on an object
the object must move in the
same direction
as the force
work done=force x distance
applies force to lift the box. box did not move no work done
the direction of
movement
is different from direction of
force
,no work done
e.g man move 20m with the box
energy changes
PRINCIPLE OF ENERGY CONSERVATION: energy cannot be created or destroyed, it is convert from one form to another
there is HIGH GPE at the highest point
HIGH KE at the lowest point
As the coaster descends, GPE is converted to KE (speed increases). As it climbs, KE is converted back to GPE (speed decreases).
