Do we weigh the same everywhere on earth?
Not completely! Although our mass remains constant, we are heavier at the poles than at the equator.
“This is because the centrifugal force generated by the Earth’s rotation is counterbalanced by a portion of the gravitational pull caused by the gravitational force.” , deciphered by Thibaut Damour, Professor of Theoretical Physics at the Institute of Higher Scientific Studies.
Indeed, the closer to the plane of rotation of our planet – the equator – the stronger the centrifugal force. This reduces the effect of the gravitational force a little. On the contrary, the centrifugal force at the poles is zero: so the effects of gravity are more significant there. “In addition, this centrifugal force formed the Earth as well This gives it the shape of a flat oval at the poles. Thus the equator is farther from the center of the Earth than the poles – by about 21 kilometers – and in fact the Earth’s gravity is a little weaker there. “So it would be more interesting to buy a kilogram of sugar in Senegal than in Greenland, laughs Jean-Louis Viniers, a geophysicist at the University of Lorraine. However, the difference in weight is still very small: only 0.2%.
According to Science & Vie No. 1252