physical activity and older americans

. When the plant or animal dies fresh carbon is no longer taken in and the C - 14, which is present, decays. Thus, the length of time a specimen has been dead may be determined by the activity of the C - 14, which remains in it. Carbon - dating has therefore become an important tool for a..

Remove air from a can by putting a little water into the can and boiling the water in it. The steam forces the air out. Close the opening and keep it below a tap, we find the can crumbling as the pressure inside the can is very small when compared to the pressure outside. ..

In the above arrangement where the cardboard is intact, water does not come out of the tumbler as the cardboard is balanced due to pressure of liquid in the tumbler and the atmospheric pressure from below. ..

Wet the rim of the plumber's force cup with water and press it against the wall to squeeze out most of the air. We find it difficult to pull the cup. (This simple principle is used to remove any blocks in holes of washbasin)..

Physical World and Measurement..

Communication Systems..

Semiconductor Devices..

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Introduction - You have learnt in the earlier chapters that flow of electrons constitutes an electric current and current can be generated from a battery or a generator. Scientists later discovered that there are many other ways of producing the stream of electrons. This knowledge has led to furthe..

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