Awhistle of frequency 589 hz moves in a circle of radius 54.6 cm at an angular speed of 16.1 rad/s. what are (a) the lowest and (b) the highest frequencies heard by a listener a long distance away, at rest with respect to the center of the circle? (take the speed of sound in air to be 343 m/s.)

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

Inside of a windmill or a dam is a that is used to transform one type of energy into electrical energy. a. motor b. generator c. transformer d. power pack

Smallest intensity of a stimulus that you can detect 50 percent of the time is