In this problem...What is the force of gravity between you and the earth...what would be the value of "r" in the equation for Newton's law of universal gravitation...i thought it would be zero since we are on the earth but zero can't be in the denominator so i'm stumped...can anyone help me out?
2007-10-16 18:04:06 · 4 answers · asked by k_hrdr 2 in Science & Mathematics ➔ Physics
The shell theorem (see reference) says that gravitationally, any spherically symmetric object is equivalent to a point mass at its center. If you replaced the earth by a tennis ball at its center of equal mass, the gravitational force would be the same.
2007-10-16 18:15:53 · answer #1 · answered by Frank N 7 · 0⤊ 0⤋
The force between the earth and I = G M m /R^2 where M is the mass of earth and R is the radius of earth.
The value of GM / R^2 at the equator is 9.81 m/s^2
Hence the force on me by earth is 70 x 9.81 = 686.7 N
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The R in the formula is the distance from the center of earth to the surface of earth [ground]. Hence it is the radius of earth and is not equal to zero.
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2007-10-16 18:16:56 · answer #2 · answered by Pearlsawme 7 · 0⤊ 0⤋
on the century at the same time as Newton lived, all of us believed there become one set of rules for gadgets the following on earth, and a diverse set of rules for celestial bodies. Newton got here to appreciate that his regulation of gravitation utilized in both area names, hence the be conscious established become extra to the call, to emphasise this aspect.
2016-10-21 07:19:16 · answer #3 · answered by Anonymous · 0⤊ 0⤋
'r' is the radius of the Earth, or more accurately, the distance between your centre of mass and the Earth's centre of mass.
2007-10-16 18:24:26 · answer #4 · answered by Anonymous · 0⤊ 0⤋