Answer:
15 N
Explanation:
According to Newton's third law of motion, to every action, there is an equal and opposite reaction. This reaction is equal in magnitude to the force acting but in an opposite direction.
Now, if the book weighs 15 N, an opposite equal force will be: N = -15 N
But the magnitude of this will be the absolute value which is 15N.
Solid and liquids are much more denser than gas because their molecules are close to each other and with that the molecules of them can't move that freely unlike the gas molecules. Also, because of being near to each other the molecules of solid and liquids became heavy making them dense.
Sure I can be your friend do you play video games
answer
60.1667 
explanation
there are four main kinematic formulas that we use in physics
= final velocity
= initial velocity
a = acceleration
t = time
x = displacement
we use an equation based on what information we have
in this question, we have initial velocity (0), final velocity, (38), displacement (12), and we want to find acceleration
so we use the equation that includes 
which is this equation 
rearrange to solve for a
plug in values
