Wich single force acts on an object in free fall (air resistance)(gravity)(friction)(flui d forces)

The particles of an ice cube at 0°c (represented by the blue circles) come in contact with the particles of juan’s hand at 37°c (represented by the orange circles). which diagram correctly represents the temperature of the two substances and the direction of heat flow?

What are similarities and differences of reflection, refraction, diffraction and absorption?

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?