Gravitational Forces: Calculating Magnitude & Acceleration

[ahealy88]

(a) Calculate the magnitude of the gravitational force exerted on a 787-kg satellite that is a distance of two Earth radii from the center of the earth= 8.48*10^-14

(b) What is the magnitude of the gravitational force exerted on the Earth by the satellite? (In Newtons)

(c) Determine the magnitude of the satellite's acceleration. (m/s^2)

(d) What is the magnitude of the Earth's acceleration (m/s^2)

 

[tiny-tim]

Welcome to PF!

Hi ahealy88! Welcome to PF!

Show us what you've tried, and where you're stuck, and then we'll know how to help!

 

[ahealy88]

Thank you! :)
I've tried the F=G(m1m2/r^2) and F=ma and I'm not getting anywhere.

 

[tiny-tim]

Thank you! :)
I've tried the F=G(m1m2/r^2) and F=ma and I'm not getting anywhere.

(try using the X² and X₂ tags just above the Reply box )

Well, have you done a) then?

If not, show us your calculations, so that we can see what's going wrong.

 

[ahealy88]

The answer to A was given to me, its 8.48*10^-14

 

[ahealy88]

I don't know how to get A; I'm completely lost in this problem.

 

[tiny-tim]

(a) Calculate the magnitude of the gravitational force exerted on a 787-kg satellite that is a distance of two Earth radii from the center of the earth= 8.48*10^-14

You know g, the gravitational acceleration at one Earth radius …

so what is the gravitational acceleration at two Earth radii?

(and then use F = ma)

 

[ahealy88]

that did not help.

what i have is the mass of earth=5.9742*10^24
G= 6.674*10^11

my equation did not add up= 6.674*10^11(5.9742*10^24 * 787 / 12756.2^2)

 

[ahealy88]

and i have no idea how to figure out b,c, & d

 

[ahealy88]

Help!

 

[tiny-tim]

what i have is the mass of Earth = …

You don't need the mass of the Earth!

You know g, the gravitational acceleration at one Earth radius …

so what is the gravitational acceleration at two Earth radii?