Page 165 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

g = Acceleration due to gravity = 9.8 metres/second 2

3 Thermal Energy: The energy associated with the random motion of particles in a substance. It is related to
temperature and is transferred through heat.
4 Chemical Energy: The energy stored in the chemical bonds of molecules. It is released or absorbed during
chemical reactions.
Conservation of Energy
- According to the Law of Conservation of Energy, energy cannot be created or destroyed, only converted from
one form to another.
- This principle allows us to analyze energy transformations in various systems, such as mechanical, electrical,
and thermal systems.

Applications
- Understanding work, power, and energy is essential for various applications, including:
- Designing efficient machines and systems
- Calculating energy consumption and costs

- Optimizing energy production and utilization
- Analyzing the performance of engines and motors
Conclusion
- Work, power, and energy are interconnected concepts that describe the transfer and transformation of energy
in physical systems.
- By understanding these concepts, we can analyze and predict the behavior of systems and devices in various
applications.

Examples
1 Find the work done to lift a load of 3 kg at a height of 200 metres.
Solution: Work done = Force Applied x Distance moved
= 3 kg x 200 metres
= 600 kg metres Ans.
2 The force acting on the piston head is 5000 newtons during power stroke. Find out the work done during this
stroke whose length is 120 mm.
Solution: Work done = Force Applied x Distance moved
= 5000 newtons x 120 mm

= 5000 newtons x 0.12 metre
= 600 newtons metres
= 600 joules Ans.
[ 1 loule = 1 newton metre]

3 A motor vehicle braked at a distance of stopping is equal to 80 metres. Tha amount of braking force applied at
the wheels is 500 newtons. What is the work done during its brake operation?
Solution: Work done = Braking force x Distance moved
= 500 newtons x 80 metres

= 40000 joules
= 40 kilo joules Ans.

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CITS : WCS - Electrical - Exercise 14