The thickness of oil spill can be measured by microwave reflection. A drone directs microwave beam from above. The two oil surfaces reflect microwave back to the drone. The refractive index is 1.5 for crude oil, and 1.34 for sea water. At one spot, the strongest reflected frequency (zeroth order interference) is 6 GHz. The oil thickness is mm.

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

In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? a. transparent -> translucent -> opaque b. opaque -> transparent -> translucent c. opaque -> translucent -> transparent d. translucent -> transparent -> opaque

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration