Answer: 81.619 kJ
Explanation:
Given
Mass of roller coaster is 
It reaches the steepest hill with speed of 
Hill to bottom is 51 m long with inclination of 
Height of the hill is 
Conserving energy to get kinetic energy at bottom
Energy at top=Energy at bottom

Answer:
• riding on a Ferris wheel whose entrance and exit are the same
• walking around the block, starting from and ending at the same house
• running exactly one lap around a racetrack
Explanation:
Displacement simply means the.change in position of an object. In a situation whereby the initial and final position are thesame, the displacement will be zero.
The statements that describe a situation with a displacement of zero include:
• riding on a Ferris wheel whose entrance and exit are the same
• walking around the block, starting from and ending at the same house
• running exactly one lap around a racetrack
Answer: B) Solid water to liquid water.
Explanation: This would be the melting of water or a transition of solid water to liquid water as energy is added.
The answer to this is Chemical property.