Arailroad freight car, mass 15 000 kg, is allowed to coast along a level track at a speed of 2.0 m/s. it collides and couples with a 50 000-kg loaded second car, initially at rest and with brakes released. what percentage of the initial kinetic energy of the 15 000-kg car is preserved in the two-coupled cars after collision

What is work? how much work is done to move an object 0 meters?

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.

Two polarizers are oriented at 24.0∘ to one another. light polarized at a 12.0-degree angle to each polarizer passes through both. what is the transmitted intensity (%)?