Manuel and Daniel are playing catch with a football. they are standing 30 meter apart Manuel throws the ball to Daniel , and it take 3 seconds for the ball to reach Daniel. how fast is the ball going

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

What is a difference between a mixture of elements and a mixture of compounds