The force acting on the boulder bringing it down the mountain? Would be gravity. Not sure about any of the multiple choice options you have
Answer:
Asthenosphere
Explanation:
The asthenosphere is a part of the upper mantle just below the lithosphere that is involved in plate tectonic movement and isostatic adjustments.
Answer:

Explanation:
As per thermal radiation we know that rate is heat radiation is given as

here we know that
T = 34 degree C = 307 K

e = 0.557


now we have




Answer:
Negative feedback caused his pancreas to produce more insulin.
Explanation:
Positive feedback is a feedback that causes an increase of product as a result of change while negative feedback is a feedback that causes a decrease in product as a result.
Negative feedback mechanism can be shown in the body as the control of blood sugar. The blood sugar is the product to be controlled. When there is an increase in blood sugar, the nerves sense a change. This change leads to secretion of insulin by the pancreas until homeostasis and then the secretion stops.