# physics

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Proponents of astrology claim that the positions of the planets at the time of a baby's birth will affect the life of that person in important ways. Some assert that this effect is due to gravity. Examine this claim with Newton's law of gravity. Calculate the maximum force exerted on the baby by the planet Mars and compare that with the force of gravity exerted by the mass of the doctor's head as she delivers the baby. Assume Mars is at its closest approach to Earth at the time. You will need to estimate the mass of a newborn, as well as the mass and distance between the doctor's head and the baby.

Which of the following are critical to solving this problem?

--Newton's law of gravitation
-Newton's 2nd Law
-constant acceleration
-equations of motion
-weight force

• physics - ,

Mass of Mars = 6.42*10^23 kg
orbit radius of Mars = 2.28*10^11 meters

orbit radius of earth = 1.49*10^11 meters

difference in orbit radii = .79*10^11 meters
G = 6.67*10^-11
You guess Mbaby and Mdoctor head

F1= G Mmars Mbaby/(.79*10^11)^2
= G (6.42*10^23)(Mbaby)/(.624*10^22)

assuming doctor .3 meter from Baby
F2 = G Mdoctorhead Mbaby/(.3 )^2

• physics - ,

Law of gravitation of course. That is what we are using.