Nico vibrates an object at different frequencies. At a certain frequency, the sound gets louder and then returns to the same volume when he moves to the next frequency. What is occurring when the sound gets louder?

The vector a? is 3.50 cm long and is directed into this page. vector b? points from the lower-right corner of this page to the upper-left corner of this page and has the components bx=-19.5 cm , by=25 cm. in the right-handed coordinate system, where the +x-axis directed to the right, the +y-axis toward the top of the page, and +z-axis out of the page, find the x-component of the vector product a? ×b? , measured in cm2.