Posts Tagged ‘friction’

In so many movies and books, gravity is simulated in space with centrifugal force. I don ‘t exactly understand how that would work. I understand it’s the concept of the friction of the floor pulling you and causing you to gain inertia and move with the platform, but before you touched a surface, wouldn’t you just be "floating" there as the station would spin around you? (This is assuming the station is in orbit). Or, for example in 2001, the Jupiter 1 had a spinning platform that allowed an astronaut to run. What forces him back to the floor after he pushes off?

I am working on a physics project in which I have to discuss different topics (in physics) that deal with power boats. I can go into detail on the friction of water, velocity, etc., but I was looking for more in-depth details and more interesting concepts. Physics is not my strongest subject, so any intellectual information would be helpful.

you find yourself out on this impossibly slick ice. There is so little friction that you can’t walk at all. No worries, you’ve got this lovely 2.5kg physics book. You throw it away from yourself giving it a speed of 8.4m/s. How much time does it take for you to reach the other side of the ice which is 15.5m away? Your mass is 75kg.

Assume that the space shuttle is just an average NASA shuttle. By "completely unaffected" by gravity, I mean that it would be able to just keep on going at the same speed indefinitely [assuming it never came into contact with other gravitational sources], because there was no friction or gravity [for example, if you jumped off the shuttle at whatever altitude you specify, you would just keep on going forever].
okay, I know that nothing can be completely unaffected by gravity. Just give me the altitude where the effect of EARTH’s gravity will be virtually zero/negligable, and you could do the things specified in the question.

A particular horizontal turntable can be modeled as a uniform disk with a mass of 200 g and a
radius of 20 cm that rotates without friction about a vertical axis passing through its center. The
initial angular speed of the turntable is 2.4 rad/s. A ball of clay, with a mass of 80 g, is dropped
from a height of 35 cm above the turntable. It hits the turntable at a distance of 10 cm from the
center, and sticks where it hits so that the clay and the turntable rotate together at a new angular
speed. Assuming the turntable is firmly supported by its axle so it remains horizontal at all times,
find the final angular speed of the turntable-clay system.
PLEASE EXPLAIN HOW TO DO IT!!