The velocity that the coaster must have at the top of a 50-foot hill to achieve a velocity of 57 feet per second is 7 feet/second.
Velocity is the rate of change of its position with respect to time.
[tex]V = \dfrac{dy}{dt}[/tex]
Given the velocity(v) in feet per second of a roller coaster at the bottom of a hill is related to the vertical drop(h) in feet and the velocity(v°) in feet per second of the coaster at the top of the hill by the formula v°=√(v²-64h).
Therefore, the velocity of the coaster at the top should be,
[tex]v^o=\sqrt{(v^2-64h)}\\\\v^o=\sqrt{[57^2-(64\times 50)]}\\\\v^o=\sqrt{49}\\\\v^o = 7\rm\ feet/second[/tex]
Hence, the velocity that the coaster must have at the top of a 50-foot hill to achieve a velocity of 57 feet per second is 7 feet/second.
Learn more about Velocity:
https://brainly.com/question/18084516
#SPJ1