Rabu, 08 Oktober 2008

Energy and Work for grade 8

1.Kind of energy :
1. Mechanical energy
a. Potential energy
b. Kinetic energy
2. Heat/thermal energy
3. Electric energy
4. Chemical energy
5. Sound energy
6. light energy

Source Energy

Slide 5
1.Solar energy
2.Wind energy
3.Water energy
4.Biogas energy
5.Geothermal energy
6.Petroleum and coal energy
7.Nuclear energy


Potential energy
Slide 7
Potential energy is influence by mass of the
object (m), height of the object to the earth
(ground) and earth gravitational acceleration
Mathematically, it is formulated by

EP = m x g x h

Ep = potential energy (Joule)
m = mass (kg)
g = gravitational acceleration (m.s-2)
h = height of the object (m)

Kinetic Energy
Is the energy an object possesses due to
the its motion.
The kinetic energy is formulated as follow :

E
k = 1/2 x m x v2

Ek = kinetic energy (Joule)
m = mass (kg)
v = velocity or speed (m.s-1)


Example :

A car move mass 1500 kg is travelling with
speed of 20 m.s-1. What is the kinetic energy
of the car ?

Mechanical energy is...
Slide 11
sum of potential energy and kinetic energy owned by the object.
Em = Ep + Ek
Example : swing



Rabu, 30 Januari 2008

physics animation

I hope this animation help you to understanding the appropriate concept.