How many components do vectors have, and what are they?

There are two components for a two-dimensional coordinate system/vector.

Explanation:

For two-dimensional vectors, such as velocity, acceleraton, etc, there are two components, the x- and y-components.

These components could be rotated or translated, depending on the coordinate system.

Instead of rectangular cartesian system, the components could also be in the form of polar coordinates, such as radius and theta (angle).

For three-dimensional vectors, such as velocity in space, there are three components, in various coordinate systems.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.