I found an answer from www.quora.com

If a ball is stationary on flat ground, what area of the ball is actually in ...

Given sphere r and distance the sphere settles into the surface material h, the contact area is A = 2•pi•r•h. Taking a golf ball on a fast green, the green is mowed  ...

For more information, see If a ball is stationary on flat ground, what area of the ball is actually in ...

I found an answer from www.khanacademy.com

2-dimensional momentum problem (video) | Khan Academy

2-dimensional momentum problem (part 2) .... If you throw a ball straight up in the air it only has vertical or y velocity. .... Assuming your calculations are correct, Sal must have set up a set of conditions that can't actually happen with ordinary balls. ... Like maybe one of them has a spring mechanism that goes off on contact.

For more information, see 2-dimensional momentum problem (video) | Khan Academy

I found an answer from www.britannica.com

Radar - Factors affecting radar performance | Britannica.com

The maximum range of a radar system depends in large part on the average power of ... metres at a frequency of 3 GHz when viewed perpendicular to the surface. ... Thus, the flat plate and the cone-sphere can have radar cross sections that ... by which moving targets are distinguished from the clutter of stationary objects.

For more information, see Radar - Factors affecting radar performance | Britannica.com

I found an answer from www.bbc.com

Forces, acceleration and Newton's laws - AQA - Revision 2 - GCSE ...

... where their resultant force is zero. Stopping distances depend on speed, mass, road surface and reaction time. Part of ... If the forces acting on an object are balanced, the resultant force is zero ... The submarine will continue with the same motion, either remaining stationary or moving at a constant speed. If the submarine ...

For more information, see Forces, acceleration and Newton's laws - AQA - Revision 2 - GCSE ...

I found an answer from www.ducksters.com

Physics for Kids: Potential Energy

The green ball has potential energy due ... If it is sitting still, it has no kinetic energy. ... For example, if you were to lift a book off the floor and place it on a table.

For more information, see Physics for Kids: Potential Energy

I found an answer from en.wikipedia.org

Ball bearing - Wikipedia

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation ... In most applications, one race is stationary and the other is attached to the ... much lower coefficient of friction than if two flat surfaces were sliding against each other. ... An angular contact ball bearing uses axially asymmetric races.

For more information, see Ball bearing - Wikipedia

I found an answer from www.scientificamerican.com

Slippery Science: Explore Friction by Launching Stuff - Scientific ...

Feb 26, 2015 ... What happens if you try the same thing on a carpeted floor or while wearing shoes? The amount of friction between your feet and the floor surface determines ... Friction is a very important part of everyday life—without it, you wouldn't be ... depending on which materials come into contact with one another.

For more information, see Slippery Science: Explore Friction by Launching Stuff - Scientific ...

I found an answer from www.grc.nasa.gov

Forces on a Soccer Ball

+ Contact Glenn ... When a soccer ball is kicked the resulting motion of the ball is determined by Newton's laws of motion. ... Lift and drag are actually two components of a single aerodynamic force acting on the ball. ... force is difficult because it depends on the details of how the flow interacts with the surface of the object.

For more information, see Forces on a Soccer Ball