Final answer:
Bathroom scales measure weight as a force and convert that to a mass unit, reading in kilograms or pounds mass. If a person exerts additional force by pushing on a nearby table, the reading increases. A bathroom scale would not read the same mass on the Moon due to its lower gravitational pull.
Step-by-step explanation:
Bathroom Scales and Weight Measurement
When a person stands on a bathroom scale, the scale depresses slightly due to the person's weight, which compresses the springs within the scale. The scale is designed to measure the force of weight in newtons or pounds and then converts this measurement into mass units, like kilograms, by dividing the force by the acceleration due to gravity (approximately 9.80 m/s2). While weight is a measure of force, the scale is calibrated to present the value as a mass, which is why it reads in kilograms or pounds mass.
If a person pushes down on a table while standing on the scale, the reading increases because part of their weight is applied to the table, which then exerts a matching force on the person that contributes to the overall force the scale measures. The scale reading would not be the same on the Moon as it is on Earth because the Moon has about one-sixth of Earth's gravity, which would affect the calculation of mass based on the weight reading.