energy,work and power

Question 1

what is the difference between work and energy

Answer 1

work is the transfer of energy from 1 object to another (to make the 2nd move by applying force)
energy is the ability to do work
work done=energy transfered

Question 2

what is the formula for work

Answer 2

Fx
force X distance

w=work in joules J
f=force in newtons N
x=distance in meters M

Question 3

what is kinetic energy dependent on

Answer 3

speed and mass

Question 4

what is the formula for kinetic energy

Answer 4

Ek= 1/2 mv squared
1/2 mass X speed squared
to calculate mv squared/2

Ek=kinetic energy in joules J
m=mass in kilograms kg
v=speed in meters per second m/s

Question 5

what is potential energy (name the 3 types)

Answer 5

stored energy an object has a result of its position/condition

gravitational potential
elastic potential
chemical potential

Question 6

what is gravitational potential and what is it dependant on

Answer 6

energy object has due to position above ground, gravitational pull
dependant on mass and height

Question 7

formula for gravitational potential

Answer 7

Ep=mgh

gravitational potential = mass X acceleration due to gravity X height (perpendicular to horizon)

Ep=gravitational potential energy in joules J
m=mass in kilograms kg
g= acceleration due to gravity in meters per second squared m/s2
h= height in meters m

Question 8

what is elastic potential energy

Answer 8

(how its being put into position)

when object is stressed/compressed it has the potential to return to its original shape/position

Question 9

examples of elastic potential energy

Answer 9

trampoline,slinky,guitar strings,hairband, slingshot,catapult,diving board

Question 10

what is chemical potential energy

Answer 10

stored in bonds inside chemicals
energy required to break bonds
energy released when bonds made:
released by combustion of fuel (CO2,water vapour) w/oxygen releases energy

Question 11

examples of chemical potential energy

Answer 11

batteries,food,petrol,dynamite

Question 12

sound energy and examples

Answer 12

caused by vibrating objects(form of kinetic)
travels as waves
balloon popping,radio,bell ringing,bell dinging on microwave

Question 13

thermal energy and examples

Answer 13

due to energy that particles of object have
(form of kinetic-particles moving)

heater,fire,sun,oven)

Question 14

light energy and examples

Answer 14

travels as waves

lit candle,flashlight,sun,stars,fire

Question 15

nuclear energy

Answer 15

nucleus of atoms

nuclear energy in hydrogen atoms is suns source of energy

Question 16

electrical energy

Answer 16

transfer of energy by means of moving electrons, easily converted

Question 17

what is the law of conservation of energy

Answer 17

energy cannot be created or destroyed, it can only be converted from one form to another

Question 18

what is mechanical energy

Answer 18

sum of kinetic and potential energy of object in a vacuum
total energy made of different proportions
special relation (transfer) between kinetic and gravitational potential energy

Question 19

what is the law of conservation of mechanical energy

Answer 19

the sum of kinetic and potential energy at any point will always be constant in any situation where there is no friction

Question 20

formula for mechanical energy

Answer 20

Emech= Ek +Ep

mechanical =kinetic + gravitational potential

all measured in joules

Question 21

what is power

give the formula

Answer 21

RATE at which work is done/energy expanded

P= W/t

power= work over time

P=power in watts W
W=work in joules J
t=time in seconds s

Question 22

1 kW =

Answer 22

1000 W

Question 23

1 MJ

Answer 23

1 000 000J