Kinetic energy is the energy in motion. The magnitude of the kinetic energy of an object depends on it mass and speed.
E = 1/2 mv2
where E is the kinetic energy
m is the mass of an object
v is the speed
Based from the given equation, the kinetic energy increases as the speed of an object increases. Moreover for a given speed, the kinetic energy increases with increasing mass. Like for example, a large sport-utility vehicle traveling at 55 mph has a greater kinetic energy than a small sedan traveling at the same speed, because SUV has greater mass than the sedan.
Potential energy is another form of energy which the object possesses by virtue of its position relative to other objects. Potential energy arises when there is a force operating on an object which we called the force of gravity. Potential energy can be calculated by the formula below:
v is the speed
Based from the given equation, the kinetic energy increases as the speed of an object increases. Moreover for a given speed, the kinetic energy increases with increasing mass. Like for example, a large sport-utility vehicle traveling at 55 mph has a greater kinetic energy than a small sedan traveling at the same speed, because SUV has greater mass than the sedan.
Potential energy is another form of energy which the object possesses by virtue of its position relative to other objects. Potential energy arises when there is a force operating on an object which we called the force of gravity. Potential energy can be calculated by the formula below:
PE = mgh
where m is the mass of an object
g is the acceleration due to gravity, 9.8 m/s2
h is the height of the object relative to some reference height
Example a rock at the top of the cliff has more potential energy and will make a bigger splash if it falls the water below than a similar rock located partway down the cliff.
Another form of energy relevant to chemistry is the chemical energy, it is a stored energy within the structural units of chemical substances; its quantity is determined by the type and arrangement of constituent atoms. When substances participate in a chemical reaction, chemical energy is released, stored, or converted to other forms of energy.
Thermal energy is the energy related to the random motion of the atoms and molecules. It can be calculated from the temperature measurements. The more vigorous the motion of molecules, the hotter the higher is the thermal energy.
Radiant energy is also called solar energy. It came from the sun and the earth's primary source of energy. It stimulates the growth of vegetation through the process known as photosynthesis and also influences the global climate patterns.
Units of Energy
The unit of energy is joule (J), in honor of the British scientist who investigated work and heat, James Joule (1882-1889). 1 J = 1 kg-m2/s2. A mass of 2 kg moving at a speed of 1m/s possesses kinetic energy of 1 joule.
Example a rock at the top of the cliff has more potential energy and will make a bigger splash if it falls the water below than a similar rock located partway down the cliff.
Another form of energy relevant to chemistry is the chemical energy, it is a stored energy within the structural units of chemical substances; its quantity is determined by the type and arrangement of constituent atoms. When substances participate in a chemical reaction, chemical energy is released, stored, or converted to other forms of energy.
Thermal energy is the energy related to the random motion of the atoms and molecules. It can be calculated from the temperature measurements. The more vigorous the motion of molecules, the hotter the higher is the thermal energy.
Radiant energy is also called solar energy. It came from the sun and the earth's primary source of energy. It stimulates the growth of vegetation through the process known as photosynthesis and also influences the global climate patterns.
Units of Energy
The unit of energy is joule (J), in honor of the British scientist who investigated work and heat, James Joule (1882-1889). 1 J = 1 kg-m2/s2. A mass of 2 kg moving at a speed of 1m/s possesses kinetic energy of 1 joule.
E = 1/2 mv2 = 1/2 (2 kg)(1 m/s)2 = 1 kg-m2/s2 = 1 J
Calorie (cal) is a non-SI unit of energy which is widely used in chemistry, biology and biochemistry. It was originally defined as the amount of energy required to raise the temperature of 1 g of water from 14.5oC to 15.5oC. 1 cal =4.184 J (exactly).
A related energy unit used in nutrition is the nutritional Calorie (note that this unit is capitalized)
1 Cal = 1000 cal = 1 kcal
System and Surroundings
When analyzing energy changes, we are concern with the well-defined parts of the universe, the system and the surroundings. The system is the portion of the universe single out for study while the surroundings are the rest of the universe outside the system. For example , in the reaction of hydrogen gas and oxygen gas in a cylinder, the system is the hydrogen and oxygen; the piston, cylinder and everything beyond them are the surroundings.
There are three types of systems, open system, closed system and isolated system. An open system can exchange mass and energy usually in the form of heat with its surroundings. Closed system allows the transfer of energy (heat) but not the mass. In isolated system does not allow the transfer of energy and mass,
A related energy unit used in nutrition is the nutritional Calorie (note that this unit is capitalized)
1 Cal = 1000 cal = 1 kcal
System and Surroundings
When analyzing energy changes, we are concern with the well-defined parts of the universe, the system and the surroundings. The system is the portion of the universe single out for study while the surroundings are the rest of the universe outside the system. For example , in the reaction of hydrogen gas and oxygen gas in a cylinder, the system is the hydrogen and oxygen; the piston, cylinder and everything beyond them are the surroundings.
There are three types of systems, open system, closed system and isolated system. An open system can exchange mass and energy usually in the form of heat with its surroundings. Closed system allows the transfer of energy (heat) but not the mass. In isolated system does not allow the transfer of energy and mass,
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