Which equation describes the sum of the vectors plotted below?

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?

What is the increase in density of a medium due to wave travel?

How does the strength of the electrostatic force between an electron and a proton compare to the strength of the gravitational force between them?