Final answer:
To calculate the allowable horsepower for an ANSI chain number 40 chain running at 2000 RPM driven by a 19 tooth sprocket, one would need to consult manufacturer's specifications or a machinery's handbook which provides the necessary standard formula or reference tables based on various factors.
Step-by-step explanation:
The question involves calculating the allowable horsepower for a ANSI chain number 40 chain driven by a 19 tooth sprocket at 2000 RPM. This is a typical problem in mechanical engineering, specifically within the subject of machine design and dynamics of machinery. Unfortunately, a standard formula or reference table is needed to find the exact allowable horsepower which is not provided here. Generally, the manufacturer's specifications or a machinery's handbook would be consulted to determine the maximum allowable horsepower for a given chain and sprocket configuration based on several factors such as the pitch of the chain, number of teeth on the sprocket, and the RPM at which the chain is operating.