What is the s. i. unit of drift velocity and electron mobility?

Why don't you see your reflection in water with waves or repples

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.