1pt. A roller coaster car is released from a standing start at the top of a 20.0-m hill. The car rolls down the hill to a point 10.0 m above the ground, then up a second hill to 15.0 m, and then down again to point X at 8.00 m above the ground. Use what
you know about the sum of the kinetic and potential energies to find the car's speed at X.
A. 11.7 m/s
B. 12.5 m/s
• C. 15.3 m/s
D. 19.8 m/s