1) Classic rollercoasters are appropriately named because the cars do not have any engines or propulsion and coast along the track after they are pulled to the top of the first large
hill (Point A) by large chains connected to motors on the ground which gives them stored,
gravitational potential energy. Picture the first hill of 140 meters high with a steep drop
below all the way to ground level. Ignoring friction between the all the car wheels and the
track, as well as air resistance (drag), what would the velocity of the cars be at the bottom
of the hill (Point X).
B
140 m
A
- 120 m
95 m
с
80 m
D
х

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.

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is