Posted by **Phillip** on Saturday, February 11, 2012 at 8:17pm.

An artificial satellite is moving in a circular orbit with a speed of 6.5 km/s and a period of 80.0 min. A retarding rocket fires in a direction opposite to the motion. This provides a retarding deceleration of 21.0 m/s2. What is the acute angle between the radius vector and the total acceleration of the satellite?

- College Physics -
**bobpursley**, Saturday, February 11, 2012 at 9:42pm
you have two acceleation vectors.

One is gravity.

Two is the rocket firing

Both of those is at 90 degrees, so the angle can be found from the tangent when adding those.

Gravity: v^2/r

you are given v (convert to m/s), but r can be found from

v^2/r=g(re/r)^2

or r=g*(rearth/v)^2

gravity acceleration= v^2/g(re/v)^2

figure that out, it is pointed down. Check my math.

Radial acceleration: 21m/s^2

angle= arctan (radial acceleration/gravityacceleration)

check all this , I did it in my head.

- College Physics -
**dark**, Saturday, February 9, 2013 at 6:58pm
bobpursley's answer is wrong. The question isn't a satellite revolving earth anyways.

- College Physics -
**dark**, Saturday, February 9, 2013 at 7:27pm
Total Acceleration will consist of Centripetal (which is in the same direction as the r vector) and Tangential (which at any given moment will be your retarding one. With that we can set up a triangle that gives us the angle needed.

Since we don't know radius we can use V=r2Pi/T and solve for Centripetal.

We get V2Pi/T= Ac. From Ac=V^2/r and using our solve for r from above.

Our answer will be |arctan( Aretarding/Ac)|:

|arctan(21/(V2Pi/T))=67.96deg

## Answer this Question

## Related Questions

- Physics I - An Earth satellite moves in a circular orbit 770 km above the Earth'...
- physics - An Earth satellite moves in a circular orbit 775 km above the Earth's ...
- Physics - An Earth satellite moves in a circular orbit 765 km above the Earth's...
- Physics Circular Motion - A satellite in orbit around the earth has a period of ...
- physics college - A rocket booster fires in space with a force of 500N and moves...
- Physics - An artificial satellite circles the Earth in a circular orbit at a ...
- physics - A satellite of mass 205 kg is launched from a site on Earth's equator ...
- Physics - A satellite of mass 220 kg is launched from a site on Earth's equator ...
- Physics - An Earth satellite moves in a circular orbit at a speed of 5800 m/s. a...
- Physics - A 50-kg satellite circles the Earth in an orbit with a period of 120 ...

More Related Questions