I'm trying to prove that a soccer ball cannot catch on fire. I'm trying to prove that by determining how fast a ball needs to go to reach that temperature, then comparing it with the fastest kick and its temperature. Right now I know that leather ignites at 212 degrees Celsius and that the fastest kick was measured at 221 km/h. How exactly would I determine the speed of an object with the temperature and vice versa. An equation should be all I need, I've tried looking for one but to no avail. Thanks.