Explain how buoyancy can defeat the force of gravity

The density of a liquid could be found by using

What type of light does this light bulb produce most (i. e. at what wavelength does the spectrum have maximum intensity)?

Edward tolman explained the results of his study by theorizing that the rats were learning about the maze during every trial but they a. were agitated because other groups were getting reinforcement b. could not remember how to demonstrate it without reinforcement c. were not motivated to demonstrate it without reinforcement d. seemed to be too lazy to actually work without reinforcement