Which English unit is used to measure work?

The unit used to measure work in the English system is the Joule, which represents the amount of energy transferred when a force of one newton is applied over a distance of one meter. Although horsepower and watt are related to work and power, they measure different aspects of energy transfer.

Horsepower measures the rate at which work is done or energy is transferred, specifically in relation to engines and mechanical systems. It provides an understanding of the engine's performance but is not directly a measure of work itself.

Watt, on the other hand, is a unit of power in the International System of Units (SI) defined as one joule per second. While watts indicate how quickly work is being done or energy is being used, again, it does not measure work in direct terms.

Pound is a unit of force rather than a unit of work, so it cannot serve as an appropriate measure of work.

In contrast, the Joule clearly defines work in a coherent manner compatible with the metric system, making it the appropriate choice when discussing measurement of work.