Aball is thrown downward from some height above the ground. at the instant before it reaches the ground, the ball's kinetic energy will be equal to which of the following? a. its  initial kinetic energy b. its initial potential energy c. the sum of  its initial potential energy and its kinetic energy d. the difference between  its initial potential energy and its  kinetic energy

Which surface feature of the moon is characterized by mountainous areas? terrae craters maria regolith

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

An ionic compound can conduct electricity when a it is dissolved in water b its crystals are ground into powder c it is in solid form d it is heated to just below its melting point