If a distance d has units of meters, and a time T has units of seconds, does the quantity T + d make sense physically? What about the quantity d/T? Explain in both cases.
Answer:
The quantity (T + d) does not make any sense because we cannot add two different physical quantities with different units and different dimensions,
i.e., we cannot add seconds with meters.
The quantity d/T makes physical sense because of the division between seconds and meters, i.e., m/s is a unit of speed.