The volume of air that must be moved by a loudspeaker cone radiating 0.10 W of acoustical power at 50 Hz = cm3. [See Fig. 19.3 in Rossing, page 424.] To displace this volume, the cone of 12-inch (30 cm) diameter speaker would have to move axially
cm.

Texture and composition are different because they are not the same aspect. texture has to do with feel and so on, where as composition is the chemical makeup which you cant touch like you can texture.

The rocks expand when there hot/warm  and contract when they are cold.

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

Imma say go with a (: