What type of energy is possessed by a pear falling from a tree, just before it touches the ground?
zero energy
kinetic energy
potential energy
kinetic and potential energy

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

What properties of a moving object are used in determining the object's energy of motion