3. after studying about recycling, members of john’s biology class investigated the effects of various recycled products on plant growth. john’s lab group compared the effect of different aged grass compost on bean plants. because decomposition is necessary for the release of nutrients, the group hypothesized that older grass compost would produce taller bean plants. three flats of bean plants (25 per flat) were grown for 5 days. the plants were then fertilized as follows: flat a = 450. g of 3 month old compost; flat b = 450. g of 6 month old compost; flat c = 0 g of compost. the plants received the same amount of sunlight and water each day. at the end of 30 days, the group recorded the height of the plants in cm.

hypothesis:
independent variable:
dependent variable:
constant (at least one):
control:
number of groups:
number of trials per group:

You are a researcher for a golf club manufacturer. you are given two identical looking cubes of a metal alloy. you are informed that they are made of the exact same material, but one is crystalline, whereas the other is amorphous. it is your job to determine which one is amorphous this one is more stress-resistant and is useful in reinforcing golf clubs. which of the following is the best way to determine which is which? a. determine the density of each cube. the more dense one is the amorphous solid. b. melt both cubes and look for a broader range of melting temperatures. the one that melts over a broader range of temperatures is the amorphous solid. c. determine the density of each cube. the less dense cube is the amorphous solid. d. melt both cubes and measure the range of melting temperatures. the one that melts over a narrower range of temperatures is the amorphous solid.