Centripetal Force and Gravity

Review Questions

Possible Open-Response Questions

Communications satellites are usually placed in circular orbits about 350,000 km above the surface of the Earth. Why don't we put them in lower orbits so that it would be easier to send and recieve radio and TV signals from them? Why don't we place them in elliptical orbits?

An object is placed exactly halfway between the Earth and the Moon. Which way will the object will fall? Why?

A supplier wants to make a profit by buying metal by weight at one altitude and selling it at the same price per pound at another altitude. Where should he buy his metals and where should he sell them? Why would this scheme not work very well?

If there is an attractive force between all objects, why do we not feel ourselves gravitating toward massive buildings in our vacinity?

The Sun exerts almost 200 times more force on the oceans of the Earth than the Moon does. Why then, is the Moon more effective in raising tides?

Comment on whether or not this label on a consumer product would be cause for concern. CAUTION: The mass of this product pulls on every other mass in the universe, with an attractive force that is proportional to the product of the masses and inversely proportional to the square of the distance between them.

Which would have the greater effect on Earth's ocean tides--a Moon with a greater diameter, or the Earth with an increased diameter? Explain.