The energy of a sound wave is most closely
related to the wave’s
(1) frequency (3) wavelength
(2) amplitude (4) speed

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

Contains chemical energy. a. heat b. light c. natural gas