Which one of the following equations related to the motion of an object is NOT correct? (Symbols carry their usual meanings)

Which one of the following is not a conservative force ?

Which one of the following statements about speed and velocity is correct?

Which one of the following about different frictional forces is correct?

An object is dropped from a height onto the floor, Which one of the following remains uniform as it falls?

Which one of the following is NOT the unit of energy?