Which object has the greater density? a piece of wood with a mass of 15 grams and a volume of 10 cubic cm or a rock with a mass of 20 grams and a volume of 15 cubic cm

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?