Heat Energy Measurement II

Physics SSS2 Second Term

Sub Theme: Conservation Principle

WEEK 8

Heat Energy Measurement II

Performance Objectives

Students should be able to;

1. Distinguish between evaporation and boiling and explain sublimation.

2. Explain the working principles of such common device as refrigerator.

3. Explain the effects of humidity on personal comfort.

Application of Latent Heat

Content

Example 1:

Calculate the energy required to vaporize 50g of water initially at 80⁰C . [Specific heat capacity of water = 4.2Jg^-1K^-1; specific latent  heat of vaporization of water = 2260Jg^-1]

Solution:

Q = Heat required to raise the temperature of water from 80⁰C to 100⁰C  +  Heat required to vaporize water

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