The difference in force per mass (N/kg) across a body, tidal force T, is approxi
ID: 1435643 • Letter: T
Question
The difference in force per mass (N/kg) across a body, tidal force T, is approximated by T = 4GMR/d^3, where G is the gravitational constant, M the mass of the body causing tides, R the radius of the body having tides, and d the center-to-center distance between the bodies. Make two calculations
(a) T that the Moon exerts on you_______
(b) T that a 1-kg melon 1 m above your head exerts on you.____________
For simplicity, let R for you be 1 m (pretend you're 2 m tall). Let d to the Moon be 3.8e8 m and to the melon be 2 m. Mass M of the Moon is 7.3e22 kg. Compare which is larger, and share this information with any friends who say that the tidal forces of planets on people influence their lives
Explanation / Answer
T = 4GMR/d^3 = 4*6.67x10^-11 *7.3 *10^22 *1/(3.8e8 m)^3
=4*6.67*7.3/(3.8)^3 *10^-11*10^22/10^24
=3.55 x10^-13 N/kg
For melon
4*6.67x10^-11 *1 *1/8 =3.34 x10^-11
the tidal force from melon is about 2 order of magnitude larger than that from the moon. So it is unlikely the tidal force from the moon will affect the human lives