What two things do i need to know to find velocity

Answer quickly (15 points) a comet is approaching earth. describe earth’s gravitational pull as the comet gets closer to it. a. remain constant b. increase c. decrease d. reversed

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

How many neutrons does plutonium -196 with an atomic number of 78.