# Energy absorbed per house; pressure in gas; mass

Hi,

I need help with these problems; would you help me?

Thank you.

1) A Carnot engine has a power output of 150 kW. The engine operates between two reservoirs at 20.0C and 500C. How much energy does it absorb per hour?

2) The internal energy in a monatomic ideal gas is 2.00 * 10^4J. The volume of the gas is 2.00 liters. What is the pressure in the gas?

3) A uniform plank with a length of 6.00 m and a mass of 30.0 kg rests horizontally across two horizontal bars of a scaffold. The bars are 4.50 m apart and 1.50 m of the plank hangs over one side of the scaffold. How far can a painter with a mass of 70.0 kg walk on the overhanging part of the plank before it tips?

https://brainmass.com/physics/internal-energy/energy-absorbed-per-house-pressure-in-gas-mass-39623

#### Solution Preview

The efficiency of a Carnot engine using an ideal gas as the working substance is 1-T2/T1

A Carnot engine has a power out put of 150 kW. The engine operates between two reservoirs at 20.0C and 500C. How much energy does it absorb per hour?

So the efficiency is 1 - (500 +273.15)/(20 +273.15). Divide the power output by the efficiency to obtain the power input. Watts are in Joules/sec. Multiply this by 3600 seconds in an hour to obtain the amount of ...

#### Solution Summary

The solution provided explains the steps for each equation.