Care sunt efectele fortelor de frecare in activitatea cotidiana si in tehnica?

What is the role of the ocular lens?

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?

Object a has a length of 3 cm, a width of 2 cm, and a height of 4 cm. object b is dropped into a graduated cylinder. it displaces 19 ml of water. the volume of object a is: a: greater than the volume of object b b: less than the volume of object b c: equal to the volume of object b