A roller coaster car is initially at rest at the top hill of its track. The car descends the frictionless track and acquires a speed of 10 m/s when it reaches bottom of the hill. Find the speed of the car when it is half-way down the hill?

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f

Acalorimeter uses the principle that thermal energy flows from hotter material to colder material until both reach the same