Take an electronic kitchen scale, a scale with a spring dial, and a balance scale into an elevator.
Put nothing on them. Indeed, press the tare button, or adjust them so that they all read zero.
When the elevator accelerates upwards, what happens?
My understanding of electric scales has improved. The load does not deform the tray (as I had thought), it just bends the strain gauge. The idea is that the scale is a bit like a beam balance with one end held rigid. What is measured is the strain on the "beam" = strain gauge as the load on the tray is increased. Rather than deform, the tray uniformly supports the load and the strain gauge, attached to a specific part of the tray, bends. Therefore my answer needs to be revised. The electronic scale measures an increase strain on the strain gauge as the tray (of mass "m") accelerates upward giving a weight of "ma".
Edited on September 8, 2018, 3:23 am
revision on Electronic scale
