You are Here: Home

# Physics again watch

1. Calculate the potential in the earths gravitational field a the position of:
a) a geosyncrhonous orbit

help:|
2. use GMm/r² = mv²/r, and v = 2pi r/T, where T is 24 hours (in seconds), to work out the radius of a geosynchronous orbit, then use Vg = -GM/r
3. Thank you!
4. A 320kg satllite is lifted from an orbity 1.2x10^6 above the surface of the earth to one which is 3.6x10^7 above the earths surface.

Calculate:
a) the initial speed of the satellite

Isnt this just v^2 = Gmearth/r ???Im not getting the right answer
5. Got it now, I forgot to add the radius of the earth
6. *screams*

Using the info given above: calculate the change in PE when the satellites orbit is changed.

Ep = Gm1m2(1/r1-1/r2)

Why am I getting the wrong answerrrrrrrrrrr???
7. (Original post by imasillynarb)
*screams*

Using the info given above: calculate the change in PE when the satellites orbit is changed.

Ep = Gm1m2(1/r1-1/r2)

Why am I getting the wrong answerrrrrrrrrrr???
Won't the change in PE be the same as the change in KE....using mv^2/r=Gm/r^2..........should give you the velocity and then u can find out the KE hence the PE............I think .....

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 27, 2004
Today on TSR

### Are you living on a tight budget at uni?

From budgets to cutbacks...

### University open days

1. University of Cambridge
Wed, 26 Sep '18
2. Norwich University of the Arts
Fri, 28 Sep '18
3. Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 29 Sep '18
Poll
Useful resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE