You testify as an expert witness in a case involving an accident in which car a slid into the rear of car b, which was stopped at a red light along a road headed down a hill (fig. 6-25). you find that the slope of the hill is u " 12.03, that the cars were separated by distance d " 24.0 m when the driver of car a put the car into a slide (it lacked any automatic anti-brake-lock system), and that the speed of car a at the onset of braking was v0 " 18.0 m/s. with what speed did car a hit car b if the coefficient of kinetic friction was (a) 0.60 (dry road surface) and (b) 0.10 (road surface covered with wet leaves)

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.