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Ahmed saied Sat 06 Nov 2010, 4:40 amEnergy, Resources and forms:
- Energy is ability to do work or to make a change.
- Work is the force acting on a body at rest, so it moves a distance in the direction of such force.
Work (W) = Force (F) × displacement (d)
(Joule) (Newton) (Meter)
Forms of Energy:
1- Mechanical energy (potential energy + kinetic energy). As the energy stored in the stretched spring.
2- Electric energy.
3- Sound energy.
4- Light energy.
5- Chemical energy.
6- Heat energy.
7- Nuclear energy.
Resources of Energy:
1- The sun (permanent source of energy).
2- The wind (renewable source of energy).
3- Food and fuels (fuels are non - renewable source of energy).
4- Water falls (renewable source of energy).
5- Nuclear reactions (used to produce electric and heat energies).
The Mechanical Energy:
- It is the summation of potential and kinetic energy of the body.
- By decreasing the potential energy of the body, the kinetic energy increases and vice versa.
The Potential Energy:
- It is the stored energy in the object due to a work done on it.
Kinetic Energy:
- It is the work done during the motion of an object or due to a moving body.
Work done = Mechanical energy = potential energy + kinetic energy.
Potential Energy:
Factors affecting the potential Energy:
1- Weight of the object.
- The potential energy of an object is directly proportional to its weight.
2- Height of the object from the ground.
- The potential energy of an object is directly proportional to its height from the ground.
Potential energy (P.E) = weight (W) × Height (h)
(Joule) (Newton) (m)
Kinetic Energy:
Factors affecting the kinetic Energy:
1- Mass of the object.
2- Velocity of the object.
- Kinetic energy of a moving body is directly proportional to the square of its velocity.
- Kinetic energy of a moving body is directly proportional to its mass. Kinetic energy (K.E) = ½ × mass (m) × (velocity)2 V2
Compare between potential energy and kinetic energy for an object:
- Energy is ability to do work or to make a change.
- Work is the force acting on a body at rest, so it moves a distance in the direction of such force.
Work (W) = Force (F) × displacement (d)
(Joule) (Newton) (Meter)
Forms of Energy:
1- Mechanical energy (potential energy + kinetic energy). As the energy stored in the stretched spring.
2- Electric energy.
3- Sound energy.
4- Light energy.
5- Chemical energy.
6- Heat energy.
7- Nuclear energy.
Resources of Energy:
1- The sun (permanent source of energy).
2- The wind (renewable source of energy).
3- Food and fuels (fuels are non - renewable source of energy).
4- Water falls (renewable source of energy).
5- Nuclear reactions (used to produce electric and heat energies).
The Mechanical Energy:
- It is the summation of potential and kinetic energy of the body.
- By decreasing the potential energy of the body, the kinetic energy increases and vice versa.
The Potential Energy:
- It is the stored energy in the object due to a work done on it.
Kinetic Energy:
- It is the work done during the motion of an object or due to a moving body.
Work done = Mechanical energy = potential energy + kinetic energy.
Potential Energy:
Factors affecting the potential Energy:
1- Weight of the object.
- The potential energy of an object is directly proportional to its weight.
2- Height of the object from the ground.
- The potential energy of an object is directly proportional to its height from the ground.
Potential energy (P.E) = weight (W) × Height (h)
(Joule) (Newton) (m)
Kinetic Energy:
Factors affecting the kinetic Energy:
1- Mass of the object.
2- Velocity of the object.
- Kinetic energy of a moving body is directly proportional to the square of its velocity.
- Kinetic energy of a moving body is directly proportional to its mass. Kinetic energy (K.E) = ½ × mass (m) × (velocity)2 V2
Compare between potential energy and kinetic energy for an object:
