Do you remember the formula for potential energy ?
PE = (mass) (gravity) (height)
If the mass and the height are always the same, then the least PE comes from the least gravity. Surely you can find THAT in the table.
A spring is an object that can be deformed by a force and then return to its original shape after the force is removed.Springs come in a huge variety of different forms, but the simple metal coil spring is probably the most familiar. Springs are an essential part of almost all moderately complex mechanical devices; from ball-point pens to racing car engines.
The order of the magnitude of the length in meters is estimated based on the average length of the object: if it is a small object then the unit would be cm and if it is a long object (like a road or something) the distance can be measured in km. Then we convert the unit we measured in into the SI unit of the meter.
Based on this, for the mentioned objects, the estimated length would be as follows:
a- ladybug: 10^-2 meters
b- your leg : 10^0 meters
c- your school building : 10^1 to 10^2 meters
d- a giraffe: 10^0 meters
e- city block: 10^2 meters
The process that produces the energy radiated by stars is nuclear fusion in the core.
For a star on the main sequence, it's the fusion of hydrogen nuclei into helium.
