Answer:
144 ft
Explanation:
h(t) = -16t² + 64t + 80
The maximum height is at the vertex. We can find the vertex of a parabola using -b / (2a):
t = -64 / (2×-16)
t = 2
The vertex is at 2 seconds. The height of the stone at this time is:
h(2) = -16(2)² + 64(2) + 80
h(2) = 144
The maximum height is 144 feet.
The true statement is that ;there is no change in the kinetic energy of the book and the potential energy of the book-Earth system increases.
We have to note that from the law of conservation of mechanical energy, the sum of the kinetic and potential energy of the book at any point remains constant.
If the book is being raised at constant speed, the the true statement is that ;there is no change in the kinetic energy of the book and the potential energy of the book-Earth system increases.
Learn more about kinetic energy: brainly.com/question/15308590
Im too young for physics, sorry!