energy and work done
basic info
definition
S.I unit
others
types of energy
chemical potential energy
elastic potential energy
electrical energy
nuclear energy
sound energy
thermal energy
kinetic energy
gravitational potential energy
its is energy an object possess due to its motion and mass.
it is energy an object possesses because of its position in a gravitational field.
conversion of energy
light bulb turned on
work done
definition
S.I unit
formula
examples
sources of energy
non renewable
renewable
example questions + answers
it is the ability to do work.
energy is converted from one form to the other. Energy can be transferred.
joule (J)
energy cannot be created or destroyed
speed increase, KE increases
KE of an object is dependent on the speed the object is moving.
slower object, lesser KE
if two objects move at the same speed, the one with higher mass will possess more KE
height increase, GPE increases
stored in an objects height
depends on the weight of the object and the height it is at.
lower the positition, lesser the GPE
when two objects are at the same height, the heavier object will have higher GPE
electrical ➡ light + heat (energy)
car moves
chemical potential ➡ kinetic (energy)
archer releases arrow
elastic potential ➡ kinetic (energy)
power station -> 10000J electrical energy for light bulb to light up
-> 8000J light energy is converted from electrical energy
-> 2000J thermal energy is converted from electrical energy
the total amount of Joules would remain the same throughout
it is when a force acts on an object, and the object moves in the same direction as the force
Joule (J) (force done on object)
force x distance moved = work done
Marie lifts up a box
She applies a force of 40N on the box. The shelf is 2m above the floor
there is work done on the box because a force of 40N is applied to move the box. the box moves in the same direction which the force was exerted. (⬆) (force applied on box is up, direction the box moved was up)
marie holds a basket and stands without moving.
she applies a force of 50N on the basket, and holds it 1m above the floor
walks with a basket
she applies an upward force of 50N on the basket and walks while carrying the basket at the same height above the ground.
no work is done on the basket. A force of 50N is exerted on the basket but the basket does not move. (force exerted was up but basket no direction for no movement)
no work is done on the basket. a force of 50N is exerted on the basket but the direction of movement by the basket is not the same direction of force exerted on it. force applied was up but direction of basket was left/right
biofeuls
fossil fuels
they are the remains of the dead plants and animals and takes millions of years to form.
chemical potential -> heat -> kinetic -> electrical (energy)
it is burnt to be used, and it can be a fuel for cars, and more , but it produces harmful gases such as carbon dioxide and sulfur oxide when burnt
geothermal energy
hydroelectric energy
solar energy
wind energy
kinetic -> electrical (energy)
GPE -> kinetic -> electrical (energy)
heat -> kinetic -> electrical (energy)
light -> electrical (energy)