It makes the data thet they collect more reliable so if they need the data again, they have already tested it a few times so therefor they know that it is right.
I believe you are right. pH is the concentration of H+. Therefore the more acidic the more H+.
Ignoring air resistance, the bullet's horizontal velocity is constant:
In 1.3 seconds, we can expect it to travel
16/9 m/s^2
negative 4/3 m/s^2
14 m/s
the last one is too detailed to do in my head while on the bus; sorry
Coulomb's Law: Force = k x q1x q2 divided distance square
where k=9x10^9 , q1 and q2 are the charge
So if you distance is halved, your force is stronger by 4 times
and if you distance is doubled, your force is 1/4
Ask me again if you aren't clear :)
