Chapter 6, Problem 43A

When Helen lifts one foot and remains standing on a bathroom scale, pressure on the scale is doubled. Does the weight reading change?

To determine

The change in the weight reading, when person H lifts his one of the foot and remains standing on a bathroom scale.

Answer to Problem 43A

There will be no change in the weight reading on the scale.

Explanation of Solution

Introduction: There are forces that are acting on a person when he stands on the bathroom scale, which are the upward force and the weight of the person.

The pressure is the ratio of force per unit area.

If a person is standing on one foot, there will be no change in the weight reading on the scale, since the mass and the gravitational force will be same.

The pressure applied to the smaller surface will be more, since the pressure is force per unit area and since the surface area is small, the pressure will be more when person H lifts one foot and keeps standing on the scale as compared to when H is standing properly with both feet down.

Conclusion:

Hence, if the pressure on the scale is doubled, the weight reading will remain same as the scale reads force, not the pressure.