question_answer 24)

Read each statement below carefully and state, with reasons and examples, if it is true or false: A scalar quantity is one that (a) is conserved in a process, (b) can never take negative values, (c) must be dimensionless, (d) does not vary from one point to another in space, (e) has the same value for observers with different orientations of axes.  

Answer:

(a) False. Kinetic energy (scalar) is not con-served in an inelastic collision. Moreover, vector quantities like linear momentum, angular momentum, etc., are also conserved. (b) False. Scalar quantities such as electric potential, temperature, etc., can take negative values. (c) False. Scalar quantities like mass, density, energy, etc., are not dimensionless. (d) False. Density (scalar) varies from point to point in the atmosphere. (e) True. The mass (scalar) of a body as measured by different observers with different orientations of axes has the same value.