(a) Explain the terms: (i) inertia; (ii) inertial mass. (b) List three factors which affect the rate of evaporation of water in a pond. (c) Two ice cubes pressed together for some time were found to stick together when the pressure was removed. Explain this observation. (d) Two vertical capillary tubes of the same diameter are lowered into beakers situated at the same level, containing liquids A and B of densities 9.2 x 10\(^2\) kgm\(^{-3}\) and 1.30 x 10\(^3\) kgm\(^{-3}\) respectively. A suction pump is used to withdraw air from the top of the liquid columns in the tubes by means of a T-piece arrangement until the liquid in A rises to a height of 26.0 cm. Calculate the height of the liquid in tube B.
Explanation
(a)(i) Inertia is the reluctance of a body to move if it is at rest or to stop if it is in motion. The more the mass of a body has the greater the inertia. (ii) Inertial mass represents resistance to any type of force. The more mass a body has the more force required to give it an acceleration. Force = mass x acceleration. (b)Factors that affect the rate of evaporation are: Wind, pressure, temperature, area of surface exposed, humidity or dryness of air. (c) Ice melts when sufficient pressure is applied to it, because increase in pressure lowers the melting point of ice. When the two ice cubes are pressed together the melting point is lowered, hence they melt to form thin layer of water between them. On releasing the pressure the water formed freezes because decrease in pressure raises the freezing point. Therefore the two cubes stick together. (d)h\(_A\)e\(_A\) = \(h_Be_B\) \(h_B = \frac{h_Ae_A}{e_B} = \frac{26 \times 0.92 \times 10^3}{1.30 \times 10^3}\) = 18.4 cm
