Why does the rotation curve of the Milky Way imply the presence of dark matter? Group of answer choices Because we directly detected dark matter at the outskirts of the Milky Way using more sensitive telescopes and instruments Because the galactic halo has retrograde and prograde orbits Because the Milky Way would not rotate without any dark matter Because stars and ISM clouds orbit slower than expected from the visible mass in our galaxy Because stars and ISM clouds orbit faster in the outskirts, which can only be explained by the gravity of invisible 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

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

Which of the following are guidelines to follow for obtaining accurate observations