Question

A lawnmower engine ejects 1.00 x 104 J each second while running with an efficiency of 0.200. Find the engine’s horse-power rating, using the conversion factor 1 hp = 746 W.

Answer 1

To find the engine's horsepower rating, we can start by calculating the power output of the engine. The power output is given by the formula:

Power output = Efficiency x Power input

In this case, the power input is the energy ejected per second, which is 1.00 x 10^4 J. The efficiency is 0.200.

So, the power output of the engine would be:

Power output = 0.200 x 1.00 x 10^4 J

To convert this power output to horsepower, we can use the conversion factor 1 hp = 746 W.

Horsepower rating = Power output / 746

By substituting the values into the equation, we can calculate the engine's horsepower rating.