Answer:
Approximately 
.
(Assuming that 
.)
Explanation:
The mechanical energy of an object is the sum of its potential energy and its kinetic energy. It will be shown that the exact mass of this object doesn't matter. For ease of calculation, let 
represent the mass of the book.
The initial potential energy of the book is
.
The book was initially at rest when it was released. Hence, its initial kinetic energy would be zero. Hence, the initial mechanical energy of the book-Earth system would be 
.
When the book was about to hit the ground, its speed is 
. Its kinetic energy would be:
.
The question implies that the potential energy of the book near the ground is zero. Hence, the mechanical energy of the system would be 
when the book was about to hit the ground.
The amount of mechanical energy lost in this process would be equal to:
.
Divide that with the initial mechanical energy of the system to find the percentage change. Note how the mass of the book, , was eliminated in this process.
.
Answer:
m g sin theta = force of object along incline due to gravity
N μ = frictional of incline on object where N is the normal force
N = m g cos theta force perpendicular to incline
m g sin theta = N μ = μ m g cos theta
μ = tan theta = tan 38 = .78
Convex lenses when placed in the air, will cause rays of light (parallel to the central axis) to converge.
Converging lenses, commonly referred to as convex lenses, have thicker centers and narrower upper and lower margins. The edges are outwardly curled. This lens has the ability to concentrate a beam of parallel light rays coming from the outside onto a spot on the opposite side of the lens.
The image created is referred to be a genuine image when it is inverted relative to the object. On a screen, this kind of image can be recorded. When the object is positioned at a point farther than one focal length from the lens, a converging lens creates a true image.
A virtual image is one that cannot be produced on a screen and is formed when the image is upright in relation to the object. When an item is positioned within one focal length of a converging lens, a virtual image is created. It creates an enlarged image of the object on the same side of the lens as the image. It serves as a magnifier.
Learn more about the convex lens here:
brainly.com/question/12847657
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An uncharged body is a body that has equal magnitude of positive as well as negative charge on it. So as soon as some charged body is placed near it, the charged body induces negative charges on the uncharged body.
