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Importance of Physical Exercise according ot age and sex

Importance of Physical Exercise according ot age and sex According to Age: Physical education is applicable for people of all ages. But programmes of physical education differ likings and dislikings for different age-groups. Not only physical exercise but also food, likings and dislikings and physical abilities are different for different age-groups. For example, physical ability of children is not equal to that of adults.  So to develop the abilies exercise through games should be introduced accordingly. Frog jumps, touch and back, crow jump or recreational games are some physical activities that can improve physical ability of children. Selection of exercise and games for adolescent should be done systematically. Standing in a line, exercise of hands and legs, running with a ball, touch and play, etc. and games and physcial exercise can be used to develop physical abilities of children. Remember, children and adolescents should not participate in weight lifting exercise. It causes h

What is thermometry?


The branch of heat relating to the measurement of the temperature of a body is called thermometry. The thermometer is an instrument used to measure the temperature of a body.

The essential requisites of a thermometer are given as under: 

1) Construction,

2) Calibration, and

3) Sensitiveness.

For the construction of a thermometer, the proper choice of a substance, whose physical property varies uniformly with rising in temperature, is essential.

1) Construction

The physical property of a substance plays an important role in the construction of a thermometer. In a mercury thermometer, the principle of expansion of mercury with rising temperature is used. The platinum resistance thermometer is based on the principle of the change in resistance with a change in temperature. The gas thermometer is based on the principle of change in volume or pressure with a change in temperature.

2) Calibration 

When a thermometer is constructed, it should be properly calibrated. The standard fixed points are selected for calibrating a thermometer. The melting point of ice, boiling point of water, melting point of silver, and the melting point of gold are taken as fixed points. The scales are built by dividing the interval between the two fixed points into equal parts. Centigrade scale is built by dividing the interval between the melting point of ice and the boiling point of water (under normal pressure) into 100 equal parts and each part represents 1 degree celsius. Similarly, the Fahrenheit scale is built by dividing this interval into 180 equal parts.

3) Sensitiveness

The instrument, once constructed and calibrated, should also be sensitive. The thermometer will be sensitive if:

  • it can detect even small changes in temperature

  • it shows the temperature of a body in a short time and

  • it does not take a large quantity of heat for its own heating from the body whose temperature is being measured.

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