3. A 200 kg roller coaster starts from rest at the top of the first hill at a height of 20 m above the ground. The second hill is 15 m above the ground. a. A physics student in line for the ride makes the observation that the speed of the coaster increases as it approaches the bottom of the first hill and slows down as it climbs the second hill. i. Define the system. ii. Describe the transfers of energy that supports the student's observations. iii. Model the energy transfer with a 2 Bar Charts (beginning to middle; middle to end). B B OL LOL OL b. Calculate the change in gravitational energy of the system from the bottom of the first hill to the top of the second hill. c. Calculate the kinetic energy of the coaster car at the bottom of the first hill.