A 46-kg woman cheats on her diet and eats a 685-Calorie (685 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut?  J (b) How many stairs must the woman climb to perform an amount o

If I add 12,183 J of energy to an ideal gas inside a balloon causing the internal energy to increase by 5185 J, how much work is done on the environment by the gas as the balloon expands?

As a gasoline engine is running, an amount of gasoline containing 18,500 J of chemical potential energy is burned in 1 s. During that second, the engine does 3,700 J of work. (a) What is the engine's efficiency (in percent)?  % (b) The burning gasoline has a temperature of about 4,100°F (2,500 K). The waste heat from the engine flows into air at about 90°F (305 K). What is the Carnot efficiency (in percent) of a heat engine operating between these two temperatures?  %

A graduate student leaves a cylinder of carbon dioxide sitting in the sun. The cylinder absorbs 25.2 J of energy while sitting in the sun. A piston in the cylinder moves upward. The carbon dioxide did 12 J of work on the piston to move it upward. Find the change in internal energy of the carbon dioxide.

A typical coal-fired power plant burns 340 metric tons of coal every hour to generate 2.5 × 106 MJ of energy. One metric ton has a mass of 1000 kg and a metric ton of coal has a volume of 1.5 m^3. The heat of combustion is 28 MJ/kg. What is the power plant’s efficiency?

A student evaluates a weight loss program by calculating the number of times she would need to climb a 10.0 m high flight of steps in order to lose one pound (0.45 kg) of fat. Metabolizing 1.00 kg of fat can release 3.77 x 10'J of chemical energy and the body can convert about 21.2% of this into mechanical energy (the rest goes into internal energy.) HINT (a) How much mechanical energy (in J) can the body produce from 0.450 kg of fat? (b) How many trips up the flight of steps are required for the 52.0 kg student to lose 0.450 kg of fat? Ignore the relatively small amount of energy required to return down the stairs. trips Need Help? Read It Watch It

Let W = (2.70 ✕ 105 J) ln(Vf /Vi). Solve for the unknown quantity in each of the following cases:   (a) the final volume Vf is three times the initial volume Vi  W= ______Joules (b) the initial volume is 1.00 m3 and the work W is 3.25 ✕ 105 J Vf =  ______ m3

At a certain location, the solar power per unit area reaching Earth's surface is 200 W/ m^2, averaged over a 24-hour day. If the average power requirement in your home is 3 kW and you can convert solar power to electric power with 10 % efficiency, how large a collector area will you need to meet all your household energy requirements from solar energy? (Will a collector fit in your yard or on your roof? ).

An asteroid made out of iron (7860 kg/m3) strikes the Earth in an areawhere the oceans are very deep. The velocity of the asteroid upon impact isthe same for most debris hitting the Earth’s atmosphere, 30 km/s.The difference in potential energy from orbit to ground is negligible at thisspeed. Assuming that 80% of the asteroid’s kinetic energy is transferred toheating the water, what volume of water (assuming a density of 1000 kg/m3)will be vaporized? We will assume that the water is taken from 70o F tothe point that it becomes steam. Also, assume that the asteriod is spherical,with a radius of 750 m.

In a process of an ideal gas, the pressure is halved while the volume is kept constant. During this process, 750J of heat flows out of gas. What is the change in the internal energy of the gas in this process?