To investigate the connection between kinetic energy and temperature, the best experimental setup would be:
Placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing one drop of food coloring in a second cup with 50 mL of water at 40ºC.
This setup allows the student to observe how temperature affects the movement of the food coloring (which is representative of the kinetic energy of the water molecules). The difference in temperature between the two cups should result in different diffusion rates of the food coloring, indicating a connection between temperature and kinetic energy.