## Introduction Area => ADARQ.org Special Content => Topic started by: adarqui on March 04, 2010, 11:10:12 pm

Title: Complete Hangtime to VJ
Post by: adarqui on March 04, 2010, 11:10:12 pm

Complete Hangtime Calculator

Complete Hangtime Calculator (input) Hangtime (output) Inches (output) Centimeters (output) Meters
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Complete Hangtime Calculator:

The hangtime calculator is for those poor souls who attempt to measure people's vertical jumps on youtube or for their own training. Simply enter in a value from 0.01 to 1 second to find the hang time. For example, using this calculator on one of your own jumps, simply cut the clip into two pieces, so that only one piece exists. The beginning of this segment should be where you are completely extended through your toes, about to leave the ground. The end of this clip is when your toes hit the surface. Insert a time or count frames to find how long you were in the air. Plug that number (for example, .83) into this calculator, and find out how high you jumped.
Title: Re: Complete Hangtime to VJ
Post by: nba8340 on March 24, 2010, 03:01:16 am
i got windows media live player, it doesn't show any of the time values in tenths, how can i figure it out?
Title: Re: Complete Hangtime to VJ
Post by: adarqui on March 24, 2010, 03:18:37 am
i got windows media live player, it doesn't show any of the time values in tenths, how can i figure it out?

using the frame count, so if it's a 30fps camera & 24 frames from toe off to landing, it would be:

24 * 0.033 = 0.792

so plug that into the hangtime calculator, it'll calc the "height" on an error of +- 2"
Title: Re: Complete Hangtime to VJ
Post by: zgin on April 30, 2010, 07:55:50 am
is this only applicable to svj?   could it be used for rvj?
Title: Re: Complete Hangtime to VJ
Post by: vag on April 30, 2010, 08:03:47 am
Everyone trying to calculate his SVJ/RVJ with this calculator might also want to take a look at this:

Title: Re: Complete Hangtime to VJ
Post by: BMully on July 25, 2010, 12:42:03 am
in sports science they stated that mj's free throw line dunk in the dunk contest lasted .92 seconds

so i am just pondering here

i'll say you need an extra inch for every inch one is shorter than MJ to dunk from free throw

6'6 -mj 40inch vert for a free throw lane dunk
6'5 - 41 inch
6'4 -42inch
6'3-43inch
6'2-44inch
6'1-45inch
6'0-46inch

this is not adding in the account of speed or reach

but gonna need ~46inch vertical b4 i do a free throw lane dunk
Title: Re: Complete Hangtime to VJ
Post by: adarqui on July 25, 2010, 04:49:52 am
in sports science they stated that mj's free throw line dunk in the dunk contest lasted .92 seconds

so i am just pondering here

i'll say you need an extra inch for every inch one is shorter than MJ to dunk from free throw

6'6 -mj 40inch vert for a free throw lane dunk
6'5 - 41 inch
6'4 -42inch
6'3-43inch
6'2-44inch
6'1-45inch
6'0-46inch

this is not adding in the account of speed or reach

but gonna need ~46inch vertical b4 i do a free throw lane dunk

interesting..

5'11 - 47
5'10 - 48
5'09 - 49 <- t-dub status off two feet

i dno man, seems like you are definitely in the right ballpark here.. reach really screws all of this data up though, and for the most part you'd have to be a single leg jumper..

regardless, those make sense.
Title: Re: Complete Hangtime to VJ
Post by: BMully on July 25, 2010, 05:14:44 am
in sports science they stated that mj's free throw line dunk in the dunk contest lasted .92 seconds

so i am just pondering here

i'll say you need an extra inch for every inch one is shorter than MJ to dunk from free throw

6'6 -mj 40inch vert for a free throw lane dunk
6'5 - 41 inch
6'4 -42inch
6'3-43inch
6'2-44inch
6'1-45inch
6'0-46inch

this is not adding in the account of speed or reach

but gonna need ~46inch vertical b4 i do a free throw lane dunk

interesting..

5'11 - 47
5'10 - 48
5'09 - 49 <- t-dub status off two feet

i dno man, seems like you are definitely in the right ballpark here.. reach really screws all of this data up though, and for the most part you'd have to be a single leg jumper..

regardless, those make sense.

is there a formula?? a trajectory formula ( have not taken physics yet haha) would be smart...but as i have not gotten that far in my education..idk 1

ok freethrow is 15ft right?
rim is 10ft up right?

reach is 94inches on me

so to dunk you need 10'5 i think and that's 125inches in the air right?

so my hand need to be 31inches in the air when i have traveled 15feet (obviously harder 2 do with a ball but let's make it simpler)

alright this is where i am stuck haha i did'nt take physics so i don't know how to do that yet

http://www.mathisfunforum.com/viewtopic.php?id=1673 --damn it i hate trigonometry but here goes

so i am guessing i'll use a 45degree angle in the jump right? cuz that'

anyway i am gonna hit my geometry book for a quick second as i just remeber arching circles..i think i can make it into an arch then maybe i'll find the answer
Title: Re: Complete Hangtime to VJ
Post by: BMully on July 25, 2010, 06:09:30 am
so i have figured out a way to get the height of the jump but speed is too much of a variable for my young mind to get

have a parabola with 3 points on the reach of the person, the second the goal on the rim, and the third is the vertical jump height

so since there is three points i am guessing you can make a line outa them and find the range of numbers which could work

so 31inches-50inches is the line i will make in height from 0 on the parabola

anyway the only way to find it out for sure rather than make a big drawing that looks cool but does nothing gravity and speed have to be in play and i am in summer vacation so i cannot do that haha

the speed of the person x vertical height = force for dunk from 15feet
Title: Re: Complete Hangtime to VJ
Post by: vag on July 25, 2010, 06:11:11 am
The formula to calculate the initial velocity ( force ) for a free throw dunk is very easy , but it it is totally different than this hangtime calculator , which is valid only for vertical displacement.
Trying not to complicate things , when there is horizontal displacement too the same force applied to the ground gives different jump 'orbits' depending on the takeoff angle. It also depends on how much force you can create at that angle , its like vertical and broad jump together.
I can get some calculations and provide you with scientific valid numbers , but that would only say how much force you must apply to get there, probably useless , the horizontal jumping ability coefficient is missing.

What you can do is that :
Do your best jump from a distance you can get rim ( say the dot line , or the free throw line ). Look how many inches you are missing , those at AT LEAST how much you need to add to your vert.

Example :
You jumped from the dot line and you touched rim at 10'4''
To dunk you need 10'10'' ( forget that 10'5'' you said unless you can balm the ball like a tennisball ).
So you are missing AT LEAST 6'' to dunk from that far out.

Ill come back to this later with some calculations on that 'AT LEAST'.

Hope it helps...
Title: Re: Complete Hangtime to VJ
Post by: LBSS on June 27, 2012, 11:49:10 am
BUMP BECAUSE CALCULATOR IS BROKEN AND MY POOR WRETCHED SELF WANTS ESTIMATES, DAMN IT.
Title: Re: Complete Hangtime to VJ
Post by: vag on June 27, 2012, 01:59:32 pm

VERT ( cm ) =  G * (Hangtime^2 ) * 12.5
VERT (inches ) = ( G * ( Hangtime^2 ) * 12.5 ) / 2.54

G = gravitational acceleration ( m/sec^2 ), an average value is 9.8 , google your own place G for more detail , small differences anyway.
Hangtime^2 = hangtime*hangtime ( in seconds )

Also, at the final result add 5'' (13cm if using the metric system ) for a better estimation, see thread reference that i made a few posts above.

BAM!
Title: Re: Complete Hangtime to VJ
Post by: Raptor on June 28, 2012, 08:21:22 am
Here the calculator works... I don't agree with starting to time from being on toes to touching the ground on toes... it should be from where the heels get off the ground to where the heels touch the ground, because when you land on your toes the heels are still off the ground and the body is still displaced upwards, so it has not landed yet. If you were to pull your toes up you'd still be in the air.
Title: Re: Complete Hangtime to VJ
Post by: LBSS on June 28, 2012, 09:07:58 am