An isotope has the same number of but different of than other atoms of the same element

Awoman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. the book has a mass of m = 1.8 kg and the coefficient of static friction between her hand and the book is μs = 0.67. no attempt 50% part (a) what is the weight of the book, fgb in newtons?

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)

What happens when a rubber rod is rubbed with a piece of fur?