Compare by doing the calculationthe gravitational force that

Compare (by doing the calculation).the gravitational force that the earth exerts on the moon to the gravitational force that the sun exerts, on the moon. (Look up needed physical data on the web.) In part A) you should have found that the force that the sun exerts on the moon is larger than the force that the earth exerts on the moon. Why then, doesn\'t sun pull the moon away from the earth? The magnitude of the force that a particle of charge q_1 exerts on a second charge q_2 that is a distance r from it is

Solution

A)

Force exerted by earth on moon,

Fem = G*Me*Mm/R^2

= 6.67*10^-11*6*10^24*7.35*10^22/(384400*10^3)^2

= 1.99*10^20 N

Force of sun on moon,

Fsm = 6.67*10^-11*1.99*10^30*7.35*10^22/(150*10^6*10^3)^2

= 4.34*10^20 N

We can clearly see that force the sun pulls moon with greater force than earth

B)

From the values we can clearly see that sun pulls the moon with greater force than the earth on it.. But you see that earth is pulled towards sun also, So, it may seem that moon lies in the vicinity of earth, It is constantly accelerating towards the sun.. though the radial distance remains fairly constant.