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a) Explain the term ‘work’ as related to energy - Leaving Cert Chemistry - Question A - 2012
Question A
a) Explain the term ‘work’ as related to energy. b) Define the term ‘energy’. c) Describe how energy is transferred in the following ways: (i) Conduction (... show full transcript
Worked Solution & Example Answer:a) Explain the term ‘work’ as related to energy - Leaving Cert Chemistry - Question A - 2012
Step 1
Explain the term ‘work’ as related to energy.
Answer
Work is defined as the process of energy transfer that occurs when a force is applied to an object causing it to move. Mathematically, it can be expressed as:
Where:
- W is work done,
- F is the magnitude of the force applied,
- d is the displacement of the object,
- θ is the angle between the force and the direction of motion.
In this context, ‘work’ is thus a measure of energy transfer resulting from the application of force.
Step 2
Define the term ‘energy’.
Answer
Energy is the ability or capacity to do work. It exists in various forms, including kinetic energy (energy of motion), potential energy (stored energy based on position), thermal energy, chemical energy, and more. Energy can neither be created nor destroyed; it can only be transformed from one form to another, in accordance with the law of conservation of energy.
Step 3
Describe how energy is transferred in the following ways:
Answer
Conduction: Conduction is the process of energy transfer through direct contact between materials. When particles of a substance are heated, they vibrate and collide with neighboring particles, transferring energy. This process occurs mainly in solids, where particles are closely packed.
Convection: Convection is the transfer of energy through the movement of fluids (liquids and gases). When a fluid is heated, it becomes less dense and rises, while cooler, denser fluid sinks, creating a convection current that facilitates energy transfer.
Radiation: Radiation is the transfer of energy through electromagnetic waves. It does not require a medium and can occur in a vacuum. The sun’s warmth reaching the Earth is an example of energy transfer by radiation.
Step 4
Suggest the way in which one can minimize heat loss.
Answer
To minimize heat loss, one can improve insulation in buildings. This can be achieved by using materials with low thermal conductivity such as fiberglass, foam, or double-glazed windows. Other methods include sealing gaps and cracks to reduce drafts, using thermal curtains, and ensuring that heating systems are efficient.