What unit is used to measure work in the International System of Units (SI)?

The unit used to measure work in the International System of Units (SI) is the Joule. Work is defined in physics as the force applied to an object times the distance over which that force is applied, and it can be mathematically expressed as:

[ \text{Work} = \text{Force} \times \text{Distance} ]

In SI units, force is measured in Newtons, and distance is measured in meters. Therefore, when you calculate work in the context of these units, the resulting unit is:

[ \text{Joule} = \text{Newton} \cdot \text{meter} ]

This means one Joule is equal to one Newton of force acting over a distance of one meter. The Joule is widely used across various scientific fields, including physics and engineering, to quantify work done in energy transfers.

The other choices represent different physical quantities. The Watt, for example, is a unit of power, which is defined as work done per unit of time. Newton is a unit of force and the Pascal is a unit of pressure. While each of these units has its own importance in physics, they do not measure work directly like the Joule does.