Astudent designs an experiment where he takes a small wood car with 1.0 inch diameter wheels and rolls it down a ramp. the student measures the speed of the car when it reaches the bottom of the ramp. the student then takes a small plastic car with 1.5 inch diameter wheels and repeats the process. finally, the student takes a small metal car with 2.0 inch diameter wheels and repeats the process a final time. the student notes that the metal car had the fastest speed at the bottom of the ramp.

the student can conclude:

a) metal cars increase speed faster than plastic or wood cars

b) cars with large diameter wheels increase speed faster than cars with small diameter wheels

c) both of the above

d) none of the above

((*hint : it's not a or b*) it is either c or d)

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

the maximum mass of nh3 is nh3 in grams