"a nurse notes that an infant with a diagnosis of failure to thrive who has been receiving tube feedings for 3 days has very dry skin and mucous membranes. the nurse verifies that all feedings have been retained, but the daily urine output is consistently 250 ml, and the infant has lost weight. what does the nurse conclude

The infant is suffering from dehydration most probably from esophageal atresia (non-development of the distal side of the esophagus, forming a closed tube) or partial/complete gut obstruction. With a urine output of 250 mL constantly, the patient will be dehydrated. The infant is diagnosed with failure to thrive and is most probably malnourished (most common cause of failure to thrive in infants is preterm birth). In the presence of esophageal atresia, along with retained feedings, the patient will also present with vomiting. In the presence of partial/complete gut obstruction, the patient will also present with distension of the abdomen. 

Wikipedia aswell can be used to solve the following questions

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on