"you have a mixture made os two substances, one with a higher density than the other. how could you separate the substances in the mixture?
a) boil the mixture so that the substances with the hightest densities turn into gas
b) add electric current to the mixture, the one with most mass will split first.
c) freeze the mixtures because the substance with the lower density will turn solid first
d) centrifuge the mixture because the substance with the highter density will be pulled to the bottom"

Ms. sullivan's class is designing a miniature roller coaster. after first setting it up, they find that it didn't have enough speed to go through the loop de loop. instead of taking out the loop, they decide to increase the height of the first hill the coaster goes down, and this adds the speed needed to make it through the loop. what would be a drawback to this plan in real life? a) no one likes loop de loops. b) there is no downside to this plan. c) a higher hill means a scarier ride. d) a higher hill takes more time and material to build.