If you know the amount of air pressure exerted on a tabletop, how can you calculate the force exerted on the tabletop? multiply the air pressure by the area of the tabletop. divide the air pressure by the area of the tabletop. divide the area of the tabletop by the air pressure. add the air pressure and the area of the tabletop.

Which term best describes the phrase “something that happens”?

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

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