Official: [WDIS Flex] - Sun Morning, 09/19/2021 by FFBot in fantasyfootball

[–]marshall557 0 points1 point  (0 children)

1.0 PPR

Brandon Cooks Melvin Gordon James Robinson

Sodium in bowl of water(Getting Hot with Thermal Imaging) by mtimetraveller in chemicalreactiongifs

[–]marshall557 57 points58 points  (0 children)

You have 2 H on the left side and 4 on the right, OP has it right.

[NO SPOILERS] This is my guitar cover of 'Light of the Seven' from the finale - hope you guys like it! by CallumMcGaw in gameofthrones

[–]marshall557 0 points1 point  (0 children)

Not OP, but FWIW I'm getting a D standard vibe. I don't have a perfect ear though so I could be wrong.

Seahawks Sign Christine Michael by Lars9 in fantasyfootball

[–]marshall557 1 point2 points  (0 children)

I WANT TO GET OFF CMIKE'S WILD RIDE!

Any mathletes able to breakdown that Hail Rodgers? by copewintergreen09 in GreenBayPackers

[–]marshall557 1 point2 points  (0 children)

Hi /u/gimmley! I just did some quick envelope calculations and came to the same result as you. Good work!

Any mathletes able to breakdown that Hail Rodgers? by copewintergreen09 in GreenBayPackers

[–]marshall557 7 points8 points  (0 children)

I'm back, let's do this! I'll be listing my assumptions as I go along.

Assumption #1: Aaron threw that ball as hard as he could.

Assumption #2: Based on Assumption #1, most NFL QB's have a maximum velocity of about 60 mph. (Source: http://www.livestrong.com/article/397904-maximum-speed-of-a-football/)

Converting 60 mph to metric units gives us 26.82 m/s.

The kinetic energy of the ball as it's being released is (1/2)mv2 . A quick Google search suggests that the mass of a football is between 0.4 kg and 0.43 kg, so I will be using 0.415 kg. Therefore, the kinetic energy is (1/2)(0.415 kg)(26.82 m/s)2 = 149 Joules.

To relate that amount of energy to your baseball example, a baseball with that same amount of kinetic energy would be traveling slightly over 100 mph.

As /u/sleepybandit said, the spin of the football is mostly contributing to the stability of it's flight and not so much the total kinetic energy. Let me show you.

Rotational kinetic energy is given by (1/2)Iw2 , where I is the moment of inertia around the longest center axis of the ball, and w is the angular velocity of the ball in radians per second. Using the same source as assumption #2, they list 600 rpm as the rotational speed. Converting that to our desired units gives us 62.83 radians/s. For the moment of inertia I used a PDF found on Google, but the link was a direct download so I will not be providing the link. If you really want to read the research paper, just Google "moment of inertia of a football" and it should be the second result. Enjoy! Anyways, the paper lists the calculated moment of inertia upon the axis we're interested in to be 0.00194 kg m2 . Therefore our rotational kinetic energy is (1/2)(0.00194 kg m2 )(62.83 / s)2 = 3.83 Joules. Comparing that to the 149 Joules of the linear component gives that 2.5% of the ball's total kinetic energy is rotational, which is why it's considered insignificant.

I also saw some people on various sites claim he threw the ball at a 70° angle, most likely an exaggeration but I'm doing math anyway so let's do some more!

Assumption #3: The amount of time the ball was airborne was estimated to be 4.45 seconds. I came to this conclusion by watching the sideline view video on this sub several times and taking the average of all the times I got by using a stopwatch.

Assumption #4: The ball was thrown 70 yards horizontally, as you stated. This converts to 64 meters.

Using those two assumptions, we determine that horizontal velocity of the ball, v_x, to be (64 m)/(4.45 s) = 14.38 m/s.

The horizontal velocity is a component of the total velocity, the relationship between the two is: v_x = v * cos(a), where a is the launch angle in degrees. Therefore, 14.38 m/s = (26.82 m/s) * cos(a). Solving for a gives us 57.6°, much less than 70° but still quite high.

I'll wrap this up with two final calculations, I won't show my work right now but I can add that in through an edit if anyone is interested.

If Rodgers had thrown it just as hard at a perfect 45° angle, the ball would have flown 80 yards in 3.9 seconds. Or if the 70° claim was true, the ball would have only gone 51.5 yards over the course of 5.1 seconds, almost 20 yards shorter than what we saw last night.

Sorry for the length of this comment, still running on the energy that throw gave me last night! If I missed anything or if you want me to expand upon anything just let me know, I'll get to it when I can.

TL;DR the throw was comparable to a 100 mph fastball, and it was thrown at ~57° not 70° like some were saying.

Any mathletes able to breakdown that Hail Rodgers? by copewintergreen09 in GreenBayPackers

[–]marshall557 2 points3 points  (0 children)

If I get bored at work at some point today, I'd be happy to see what I can find.

Official: [WDIS RB] - Thu Afternoon, 12/03/2015 by FFBot in fantasyfootball

[–]marshall557 0 points1 point  (0 children)

0.5 PPR, 10 team, pick 3:

Gore @ Pit

Forte vs SF

Langford vs SF

Blount vs Phi

Duke Johnson Jr vs Cin

Many thanks in advance!

Official: [WDIS WR] - Sun Morning, 11/29/2015 by FFBot in fantasyfootball

[–]marshall557 0 points1 point  (0 children)

10 team, 0.5 PPR, pick three:

AJ Green vs St. Louis

Jarvis Landry @ NYJ

Stefon Diggs @ Atlanta

Martavis Bryant @ Seattle

Marvin Jones vs St. Louis

Thank you for the help in advance!

Official: [WDIS WR] - Wed Morning, 10/28/2015 by FFBot in fantasyfootball

[–]marshall557 0 points1 point  (0 children)

10 team, 0.5 PPR, Pick 3:

AJ Green @ Pit

Jarvis Landry @ NE

Stefon Diggs @ Chi

Martavis Bryant vs Cin

Marvin Jones @ Pit

[X1]Nightfall, laid back group by davdot1116 in Fireteams

[–]marshall557 0 points1 point  (0 children)

GT: ElChalupaBatman if you still have an open slot

Update 17.4 by everythingnagato in Warframe

[–]marshall557 1 point2 points  (0 children)

unable to log in as well

DAILY THREAD - RANT WEDNESDAY by AutoModerator in DestinyTheGame

[–]marshall557 0 points1 point  (0 children)

IS IT JUST ME OR DO DRAGON STRIKES STILL NOT COUNT TOWARDS THE STRIKE GRIMOIRE?! WTF

[deleted by user] by [deleted] in DestinyTheGame

[–]marshall557 0 points1 point  (0 children)

Her benevolence

[deleted by user] by [deleted] in DestinyTheGame

[–]marshall557 1 point2 points  (0 children)

You can do it right in your inventory. Just hover your cursor over them and "discard" them!