1 / 8

Matter and Energy

Matter and Energy. Drill. Answer the following: List 3 types of energy: List 2 types of work:. Matter and Energy. Thermodynamics - “the study of systems and energy transfer”.

maris
Download Presentation

Matter and Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Matter and Energy

  2. Drill Answer the following: • List 3 types of energy: • List 2 types of work:

  3. Matter and Energy Thermodynamics - “the study of systems and energy transfer” On a day in January, a household digital thermometer gives a reading of 30oC; what is the absolute temperature outside? Known: A thermometer reads 30oC Find: Absolute temperature read by thermometer [K] Sketch: Assumptions: N/A Solution:

  4. Matter and Energy Thermodynamics - “the study of systems and energy transfer” A spherical balloon has a diameter of 3m. The air trapped inside has a specific volume of 0.94 m3/kg. Determine the weight of the air inside the balloon assuming the acceleration of gravity is 9.8 m/s2. Known: A sphere is filled with air (D=3m, v = 0.94 m3/kg) Find: Weight of the air, [N] Sketch: Assumptions: Closed System, g = 9.8 m/s2 D = 3m Solution:

  5. Matter and Energy Thermodynamics - “the study of systems and energy transfer” A manometer filled with water is used to measure the pressure of a gas in a tank. The water (ρ = 990 kg/m3) is displaced by a height of 0.025meter. What is the gage pressure of the gas in the tank? What is the absolute pressure? Known: A water manometer measures gas pressure (ρ = 990 kg/m3), h = 0.025 m Find: Pressure of gas in tank, Ptankin Pa; Absolute pressure of gas in tank, Pabsin Pa Patm Sketch: Tank Assumptions: Patm = 101.3kPa, Ptank = P1 , g = 9.8 m/s2 Solution: Ptank = P1= ρgh Ptank = (990 kg/m3)(9.8 m/s2)(0.025m) Ptank = 242.6 Pa Pabs = Ptank+ Patm= 242.6 Pa + 101.3 kPa= 125.4 kPa

  6. Matter and Energy Thermodynamics - “the study of systems and energy transfer” A vertical piston-cylinder device (D = 10 cm) contains a trapped mixture of gases. The piston (m = 3 kg) falls and compresses the gas mixture from 4 m3 down to 1.2 m3. How much work is done by the piston on the gas mixture? vertical piston-cylinder Known: A gas mixture is compressed inside of a piston-cylinder Find: Work done by the piston, [kJ] Sketch: Assumptions: Closed System , Vertical-piston cylinder -> Isobaric Solution: In this case, the work is negative; that implies that this work is going into the system.

  7. Matter and Energy Thermodynamics - “the study of systems and energy transfer” A piston cylinder containing a gas is compressed. The work done on the system during compression is 60 kJ and the change in energy of the system is 300 kJ. Find the magnitude and direction of any heat transfer associated with this process. Known: A gas is compressed inside of a piston-cylinder Find: Q, [kJ]; Direction of heat transfer Sketch: Assumptions: Closed System The work is going into the system, so we must give it a negative sign… Solution: The sign on the heat transfer is positive, so heat is flowing into the system.

  8. Matter and Energy Thermodynamics - “the study of systems and energy transfer” Energy can go into or out of a system as either work or heat …so far we’ve covered: • Work: • Mechanical Work = F x d • Expansion/Compression Work = • Energy, (E): • Potential Energy (PE) = m g h • Kinetic Energy (KE) = • Internal Energy (U) } E = PE + KE + U • Heat: • Heat (Q)

More Related