a person is sitting on the last bench can see clearly see things written on book but cannot see them distinctly on board. what types of lens is this concave or convex​

Current 1 of 8.4 a runs for 240 seconds and then stops. current 2 is 10.5 a. how long does current 2 have to un to deliver the same amount of charge as current 1? 88.28 192 s 2016 s 21,000 s

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

The coefficient of friction is a number that represents the resistance to sliding between two in contact with one another.