Question

Planet A and Planet B are in circular orbits around a distant star. Planet A is 6.0 times farther from the star than Planet B. Find the ratio of their speeds. Va/Vb.

Answer 1

aplay centripatal force condition for circular motion with only gravitational force, the each planet
do you see how to proceed??

Answer 2

hey tell me first the diagram i drawn is correct or not??

Answer 3

here u ll see the force is gravitational force
now we will compare it with cetrepetal force

Answer 4

let mass of star=m
mass of planet A =m1
mass of planet B=m2
F=Gm1m/r^2.......................(1)
centrpetal force F=mvA^2/r.............(2)
by comparing equation 1 and 2
vA= sqrtGm1/rA
similary
vB=sqrt Gm2/rB

u are given dat rA=6rB

by solving u ll get
vA/vB=sqrt m1/6m2

Answer 5

So its \[\sqrt{1/6}= .4082?\]

Answer 6

but u are not given mass so how can we asume that m1 and m2 are equal so in ratio u have to put m1 and m2 too..

Answer 7

no no no
heena in your comparition of equation 1 and 2 you have M(of planet) on your final formula.