Suppose you spend 30.0 minutes on a stair- climbing machine, climbing at a rate of 90.0 steps per minute, with each step 8.00 inches high. If you weigh 150. lb and the machine reports that 600. kcal have been burned at the end of the workout, what efficiency is the machine using in obtaining this result? If your actual efficiency is 0.18, how many kcal did you actually burn?

A refrigerator has a coefficient of performance of 4.0. When removing 2.4×104 J from inside the refrigerator, (a) How much energy is sent into the environment?

A test model for an experimental gasoline engine does 90 J of work in one cycle and gives up 62 J as heat. What is the engines efficiency? Show the procedure, result with units and direction Your answer

Question 6. in one cycle, a heat engine does 700J of work and releases 1450 J of heat to a lower-temperature reservoir. What is the efficiency of this engine, in percent?

Problem 3: Suppose a subject on a treadmill puts out work at the rate of 95 W while consuming oxygen at the rate of 2.00 L/min. Assume this rate of oxygen consumed corresponds to a power output of 700 W. What is the percent efficiency of the subject? 7 (%) = ||

A freezer has a coefficient of performance of 6.30. It is advertised as using 436 kWh/yr. Note: One kilowatt-hour (kWh) is an amount of energy equal to running a 1-kW appliance for one hour. Energy used in a single day - 4360000 J Energy removed from fridge in a single day - 27468000 (c) What maximum mass of water at 22.5°C could the freezer freeze in a single day (in kg)? (The latent heat of fusion of water is 3.33  105 J/kg, and its specific heat is 4186 J/kg · °C.)

A coal-fired power station is a huge heat engine. It uses heat transfer from burning coal to do work to turn turbines, which are used to generate electricity. In a single day, a large coal power station has 2.50×1014 J of heat transfer from coal and 1.48×1014 J of heat transfer into the environment.                                                                                                  (a) What is the work done by the power station?                                            (b) What is the efficiency of the power station?(c) In the combustion process, the following chemical reaction occurs: C + O2 → CO2 .This implies that every 12 kg of coal puts 12 kg + 16 kg + 16 kg = 44 kg of carbon dioxide into the atmosphere. Assuming that 1 kg of coal can provide 2.5×106 J of heat transfer upon combustion, how much CO2 is emitted per day by this power plant?