What determines how much kinetic energy an object has? A. Mass and speed/velocity

B. only speed

C. Only mass

D. Height and mass

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?