26. Keenan found the mass of a book to be 4.56*10^ -2 kg . What is the mass of the book in milligrams?

c

explanation:

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.