Physics GRE Discussion Forums

Hi everyone,

this problem confused me a bit. I know I can find the centripetal acceleration and set it equal to the gravitational force, but when they ask about "orbiting" speed it made me think of escape velocity and such... the v I get is okay for orbiting? Here's the problem:

The curvature of Mars is such that its surface drops a vertical distance of 2 m for every 3600 m tangent to the surface. In addition, the gravitational acceleration near its surface is 0.4 times that near the surface of Earth. What is the speed a golf ball would need to orbit Mars near the surface, ignoring the effects of air resistance?

anyone able to offer more insight into this one?

it is problem 22

it is a geometry problem. the radius changes and so you use centripetal forces... it is way to hard for the current exams.

orbiting around the surface...
supposedly the surface is rounded... and it's a circle...

have you checked http://grephysics.net ?

mhazelm wrote:Hi everyone,

this problem confused me a bit. I know I can find the centripetal acceleration and set it equal to the gravitational force, but when they ask about "orbiting" speed it made me think of escape velocity and such... the v I get is okay for orbiting? Here's the problem:

The curvature of Mars is such that its surface drops a vertical distance of 2 m for every 3600 m tangent to the surface. In addition, the gravitational acceleration near its surface is 0.4 times that near the surface of Earth. What is the speed a golf ball would need to orbit Mars near the surface, ignoring the effects of air resistance?

anyone able to offer more insight into this one?