Thread: Inertia
View Single Post
Old December 5th, 2016, 04:17 AM   #5
Senior Member
Join Date: Mar 2014
Location: Lomita, Ca, work in El Segundo, CA
Posts: 980
Smile two more cents...not worth much more...none the less

I asked a couple of world class skaters today if they knew what “inertia jumping” was?

1) One replied what is inertia?

a : a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force.

1a)She then replied it must mean the boots and plates are stiff.

2) The second person I asked graduated in physics and she said” it must be a fancy name for jumping”.

3) So I have a tendency to believe a roll line energy plates wants to go in a straight line and not be effected by the antics of jumping. And when landing to continue in that “straight line”.

3a) The stiff boots would aid in making sure you are not leaning and causing the jump to wobble at take off. A lean in effect makes the jump want to curve and edge. If you want to jump straight up you don’t want to lean.

4) Back to the inertia, so when you do a base 360 two footer. Your suposed to come up on flats. Do one rotation only in the air. Then land flat. So where does the inertia come from, once your in the air you can't take advantage of static friction.
They say you are converting kinetic energy, in a straight line to potential energy, energy for jumping up and down/potential energy.

The point is you want “flat” skates or skate that don’t lean and commit to a premature curvature unless wanted like going into a spin, which is a completely different take off than a jump.
5) So, I did a few (off skate). At least for me, I find, I cheat. To come around (thinking as if I am skating backward) ccw. I come off my left foot a tiny bit before my right. So the right is pushed around the left. The left is my pivot. Then I land flat (hopefully). It looks like a base jump unless you inspect it closely.
I think the base jump is similar to the mapes except you use the right foot as a “pole vault” to get you into the air. Kinetic straight line energy into up and down/potential energy.

As far as the rotation goes, I’m not sure but your arms swinging in a circle help with the rotation, which is the square of the velocity and inversely portional to the radius. Swinging the arm hard to get more rotation and bring your arms in to make the rotation go faster.

two more!

Larry O and happy jumping. Glad to see you have some jumpers to watch. That is the spirit!
larryoracing is offline   Reply With Quote