I NEED HEL PLEASE THANKS! What will happen to the pitch of a sound as that sound’s source approaches an observer? Explain why this happens, based on what you have learned about wave properties.

F500 j of energy were added to 1 kg of each of these samples, which would experience the least temperature increase?

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.