How fast would you have to launch a ball at 45 degrees above the horizontal to reach a height of 49 meters in the air? [must show work]

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

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?