Calculating Orbital Periods in Saturn's Rings

[solo]

i have no idea how to do this :(

Venus is an average distance of 1.08x10^8 km from the sun. Estimate the length of the Venutian year given that the Eearth is 1.50x10^8 from the sun on the average?

answer in years.
one more :(

the rings of saturn are composed of chunks of ice that orbit the planet. the inner radius of the rings is 73,000 km, while the outer radius is 170,000 km. The mass of saturn is 5.69x10^26 kg.

a) find period of orbiting chunk of ice at inner r
b) find period of orbiting chunk of ice at outer r

im thikning I am going to use the formula: F = m1m2 / r^2 but I am not sure how to approach it

help would be appreciated


thanks dudes

 

[solo]

F = m v^2 / r is centripetal force right

and thanks for the help

 

[solo]

coudl you please clarify how to use the radius and orbital velocity to find the period?

my texctbook doesn't give a good explanation?

thanks

F = m v^2 / r

so it would be G m m(e) / r^2 = m v^2 / r

what would m(e) be

 

[solo]

yes thank you it is finally clear

G ( 5.69 x 1-^26) / (170,000,000)^2 = v^2/r

finally

i got it :D