Catching fire while moving

[Super_Ascended_Sean_Pazdera]

How fast would someone be going if they were to instantaneosly have their entire body catch fire while moving?

 

[Dust_Collector]

I think that's somewhere around mach 20.

 

[Crimson_Azoth]

Depends on what the person was wearing. A naked person wouldn't catch fire until Mach 5 (according to data from NASA), but someone wrapped up in a bunch of clothes would catch fire at the leasurely pace of 2500 kph or Mach 2.

 

[Super_Ascended_Sean_Pazdera]

Depends on what the person was wearing. A naked person wouldn't catch fire until Mach 5 (according to data from NASA), but someone wrapped up in a bunch of clothes would catch fire at the leasurely pace of 2500 kph or Mach 2.

This is the feat.

 

[Crimson_Azoth]

The jock? Ok, give me a sec

 

[Crimson_Azoth]

American Football armour is made of polycarbonate. Polycarbonate has has a ignition point of 853.15 kelvin. I will assume that the temperature is rising from room temperature, or 293.15. Which means that the polycarbonate shell needs to get 560 K hotter.

Specific heat of polycarbonate=1.3kj/kg K

Density=1.22g/cc

I will assume that the zombie is heating up just the front of his helmet, and the fire is trailing back, which is a half-sphere with no core. The helmet has a diameter of 40.64 cm, and a thickness of 1.27 cm (standardised) That means that the total volume of the helmet is approx 25000 cc. That means that it weighs 1.525 kgs.

560 x 1.525 x 1.3 = 1110.2 kilojoules or 3,642,388.4473 newtons of force exerted by the charge. Just FYI, that makes the All Star Wall Class with this charge.

Time for the acceleration formula! A=F/M. Your average American Football player weighs 113.398 kilograms.

3,642,388.4473 / 113.398 = 32120.39 ms^-2

Now, to turn that into speed. V=AT. The power of a stopwatch tells me that that he charges for 0.13 seconds before his helmet catches on fire.

32120.39 x 0.13 = 4175.65 m/s or Mach 12.17 | Hypersonic+

Sorry that this took so long, this was actually kinda tough for me to wrap my head around.

 

[Super_Ascended_Sean_Pazdera]

Wow! Thank you!

This actually upgrades the Plants vs Zombies protagonist's speed to Hypersonic+ because he can easily react to All Star Zombies charging in PvZ 2 (as well as scales to Super Brainz and the Plant Heroes)

 

[Crimson_Azoth]

Always happy to help. If you are required to make the calculation into blog form, just copy and paste my version across with a link to the feat.

 

[Super_Ascended_Sean_Pazdera]

Thx.