Neil armstrong, the first human being to step on the moon, left a foot print that is essentially unchanged nearly 50 years later. how is it possible for this, and all the other footprints, tracks and markings, left on the lunar surface to remain unchanged for so long?

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Aman throws a football straight into the air. as it rises, it slows down. which type of energy is the football gaining?

One form of energy can be another type of energy. a. created to form b. transformed into c. destroyed and then created to form