# Homework Help: What speed would a satellite have to be placed to make it into orbit?

1. Oct 26, 2012

### joe426

1. The problem statement, all variables and given/known data

2. Relevant equations

F = G(m1m2/r2)

3. The attempt at a solution
Well the height of Mt. Everest is 8,848 m. And I'm guessing the no atmosphere and not turning on an axis is just to setup the ideal problem. But from there I dont know how to set up the equation so that the satellite is placed into orbit.

2. Oct 26, 2012

### Staff: Mentor

What's the circular orbit speed for a satellite orbiting at an altitude of 8848m?

3. Oct 26, 2012

### joe426

I dunno. How would I find it without given mass?

4. Oct 26, 2012

### joe426

I know that centrip acceleration is equal to v^2 / r. Would I set that to 0 and solve for v?

5. Oct 26, 2012

### Staff: Mentor

Nope. Right formula, but the centripetal acceleration won't be zero. What acceleration will balance it to make the total come out to zero?

6. Oct 26, 2012

### joe426

94 m/s?
Not sure what you mean by, "balance it to make the total come out to zero?"

Last edited: Oct 26, 2012
7. Oct 26, 2012

### Staff: Mentor

The radius of a circular orbit must be constant (or else it wouldn't be a circle!). That means the net radially-directed acceleration (or force) must be zero. What two accelerations act to reach a balance for a circular orbit? Or in other words, what two forces are acting?