Final answer:
Particles in a hot pan collide quickly initially due to their high kinetic energy and then slow down as they lose energy upon collision with a cooler surface, leading to a temperature equilibrium.
Step-by-step explanation:
The fast-moving particles in a hot pan collide more slowly due to a decrease in temperature. When particles in a higher temperature region, which have more kinetic energy, collide with a cooler surface, their energy decreases after the collision. This leads to the thermal energy flowing from the high temperature substance to the low temperature one, causing the temperature of the former to decrease and the latter to increase. As a result, the kinetic energy of the molecules in the hotter region will reduce, while that of the lower temperature region will increase until thermal equilibrium is reached. In summary, the particles in a hot pan start colliding more quickly but then gradually slow down as the temperature between the contact surfaces equalizes.