1. Skylab 1, the first American space station, had a mass of about 68 t. It was launched into orbit 435km above Earth's surface. Calculate the gravitational field strength at the location of Skylab 1 at this altitude.
2. The blade of a 22 table saw has a diameter of 25.4cm and rotates with frequency of 750rpm, what's the magnitude of the centripetal acceleration of the edge of the blade?
3. A star in the Andromeda galaxy is found to have a planet orbiting it at an average radius of 2.38 x 10^10 meters and an orbital period of 4.46 x 10^4 seconds. What is the star's mass?
If the planet had an orbital period of 6.19 x 10^6 seconds, what would the orbital radius be?