How is horsepower calculated?

Horsepower is a unit of measurement that quantifies the power output of an engine or motor. The correct method to calculate horsepower in the context of rotational systems involves using torque and the engine speed measured in revolutions per minute (RPM).

The formula for horsepower derived from torque is given by:

Horsepower = (Torque (lb-ft) x RPM) / 5252

This equation illustrates that horsepower can be directly derived from the torque produced by an engine and the rotational speed at which that torque is being delivered. The constant 5252 is used to convert the units appropriately based on the definitions of horsepower, torque, and RPM.

In terms of automotive applications, this is particularly relevant because it allows for the understanding of how effectively an engine converts fuel into motion. Torque reflects the rotational force, while RPM indicates how fast the engine is working. Both of these factors are essential for determining the overall power output in horsepower.

The other methods of calculation provided in the options refer to different relationships. For instance, calculating power using force and velocity pertains more to linear applications than rotational systems, thus it does not directly give horsepower in a context aligned with engine measurements. Similarly, pressure times volume relates to other physical systems, such as thermodynamics, rather than