Question

A mass is suspended on a spring scale. The scale shows a reading of 5N and stretches a distance of 0.2 meters from its relaxed length.
1)What is the spring constant of the scale?


)If this scale was taken to a planet that has a mass 4 times larger than the earth and a radius 4 times greater than the earth, what would the reading on the scale be when the mass was suspended on it?

2)If this scale was taken to a planet that has a mass 4 times larger than the earth and a radius 4 times greater than the earth, what would the reading on the scale be when the mass was suspended on it?

Answer 1

1) The definition of spring constant is force divided by the change in length. Do the calculation.
2) The accleration of gravity at the surface of a spherical body is proportional its mass and inversely proportional to the square of the radius.
4/4^2 = 1/4 of the Earth's value of g. A given mass will stretch a spring scale 1/4 as much.