Question

when gasoline is burned in the cylinder of an engine, it creates a high pressure on the piston. if the pressure is 100 pounds-force per square inch [psi], and it moves the 3 inch diameter piston a distance of 5 centimeters in 0.1 seconds [s], how much horse power [hp] does this action produce?​

Answer 1

Answer : power = 2.09 hp

Explanation :

It is given that,

Pressure, P =  100 pounds-force per square inch

Radius, $r=\dfrac{3}{2}\ inch=1.5\ inch$

Distance, d = 5 cm = 1.96 inch

We know that,

$power=\dfrac{work}{time}$

$\because Work=F.d$

And $Force=Pressure\times Area$

So,

$power=\dfrac{P\ A\ d}{t}$

$power=\dfrac{100 \ pounds \ per \ square\ inch\times 3.14\times (1.5\ inch)^2\times 1.96\ inch}{0.1\ s}$

$p=13847.4\ pounds-inch/s$

$p=\dfrac{13847.4}{12}\ Pound-foot/s$

We know that,

$1\ horsepower=550\ foot \ pounds \ per \ second$

power = 2.09 hp

So, this action will produce power = 2.09 hp.