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Use the kinetic theory of gases to explain why the pressure inside a container increases when the temperature of the air inside it rises. Assume that the volume of the container remains constant.

The kinetic theory of gases states that a gas consists of many molecules in constant motion. A rise in temperature increases the mean speed of these molecules, and therefore their momentum (=mv). The increas...
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Answered by Epen T. • Physics tutor
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What is the difference between a scalar and a vector?

A quantity that has magnitude (size), but no direction, is a scalar. A quantity that has magnitude (size) AND direction is a vector. Scalar quantities just have a magnitude. The direction does not matter. Ex...
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Answered by Alex V. • Physics tutor
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An atom can become excited by the absorption of photons. Explain why only photons of certain frequencies cause excitation in a particular atom.

Electrons in an atom occupy discrete energy levels. An electron can only be excited to another level if it absorbs the exact amount of energy as the difference between the two levels. Therefore the energy of...
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Answered by Arinjay J. • Physics tutor
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A cannon can fire a cannonball at 20m/s. A sandpit is placed at a distance of 40m away. At what angle should the cannon be fired in order for the cannonball to land in the sand.

Assume: No air resistance Sandpit of negligible height *** Steps (To be explained on whiteboard in full) Draw a diagram First look vertically Then look horizontally Formulate final equation for angle Sub in ...
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Answered by James G. • Physics tutor
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What is the difference between a scalar and a vector?

A scalar is a value that has only a size (otherwise known as magnitude), not a direction. A scalar is unaffected by the direction in which the object concerned is travelling. Examples include kinetic energy,...
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Answered by Sam T. • Physics tutor
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