Question

Please answer the following questions below:

Read each of the examples below, and indicate which is an example of positive feedback and which is an example of negative feedback. Also provide at least one example of a threshold that might be observed within the system as it is described.

Feedback Type	Process
Positive:       _______ Negative:     _______	1. When a human’s body temperature increases beyond 98.6 ºF, it normally releases water through the pores. As this water is evaporated, the transfer of latent heat reduces temperature at the skin surface. THRESHOLD:
Positive:       _______ Negative:     _______	2. When a human’s body temperature decreases below 98.6 ºF, the body metabolizes stored food, raising the temperature of the body. THRESHOLD:
Positive:       _______ Negative:     _______	3. A sound system is used to amplify the signal from a microphone placed on a guitar. If that microphone is positioned in front of the speakers, the signal is amplified, then received and re-amplified. The greater the input signal from the microphone, the greater the output signal from the speaker, which in turn becomes input for the microphone. THRESHOLD:
Positive:       _______ Negative:     _______	4. Continents are large bodies of rock and soil that float on a flexible (by geologic standards) layer of mantle. Erosion caused by wind and water lowers the surface elevation of continents (or parts of continents). But as the erosion lowers the elevation, it also reduces the mass of a continent. This causes the continent (or part of it) to rebound, so that its elevation is not reduced as much as expected. THRESHOLD:
Positive:       _______ Negative:     _______	5. An engine experiences a leak in the water jacket (the part of the engine that allows the coolant to flow through it). As the engine heats up, steam and water expand and are forced through the leak. As the water escapes, the engine loses its ability to remain cool, and thus its temperature increases. As its temperature increases, more water is lost. THRESHOLD:
Positive:       _______ Negative:     _______	6. In the early 1980s, tropical rain forests were being cleared rapidly. This led some to predict that all rain forests would disappear from the Amazon region by 2000, and from the entire world by 2020. This led activists and governments to work at reducing deforestation. As of 2000, a lot of rain forest has been lost, but a majority remains. The earlier increase in clearing led to efforts to decrease clearing. THRESHOLD:
Positive:       _______ Negative:     _______	7. As the earth’s temperature increases, more evaporation takes place. As the evaporation takes place, clouds are formed. The clouds, being white, reflect a lot of incoming solar radiation (sunlight) back to space. This reflectance of energy to space has the effect of lowering temperatures at the surface. THRESHOLD:

Answer 1

Please find the answer sheet attached Answe 1, 2, 3 and 5 are Positive. Answer 4 is Negative, Description are in the answer sheet.