homework and exercises - Does a 27 hp engine output the same amount of energy as lifting a 1 ton stone block almost 3 meters per second?

I’m trying to get a sense of how much energy a 27 horsepower engine outputs.

27 hp $=$ 20 133 watts (joules/second). Potential energy can be calculated as $E = mgh$ where $g = ~9.8\ m/s^2$ on earth. Therefore,

$m = \frac{20133\ W}{9.8\ m/s^2} = ~3000\ kg$.

So, for example, if you use a 27 hp engine to pump hydraulic fluid. Would it output as much fluid as a 3000 kg stone block pushing down a piston at 1 meter per second? Everything else equal.

Answer

1 HP = 745.7 Watts. 1 Watt is a Joule/second, which corresponds to the measure of the rate of energy.

27 HP= 20133 Joules/second. The output of a 27 horse power engine is 20133 Joules per second. The engine of a car is rated a t 50- 120 KW. This engine can make work 672 light bulbs of 30 W. Your analogy is quite right if the pressure of the piston is independent of time.