WAEC Physics 2021 Theory — Question 15

Model answer

(i) Dew point is the temperature at which the water vapour in a given volume of air is just sufficient to saturate it, so that it begins to condense into liquid water. (ii) Metal is a much better conductor of heat than rubber, so at night metal loses heat (and cools below the dew point) faster than rubber, causing dew to form on it more quickly.