1 / 19

GUPPESS

GUPPESS. Problem solving approach G iven U nknowns P icture P rinciple E quation(s) (Governing) S olve (Algebra first!) S ubstitute (given values). Example.

phelan-owen
Download Presentation

GUPPESS

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. GUPPESS • Problem solving approach • Given • Unknowns • Picture • Principle • Equation(s) (Governing) • Solve (Algebra first!) • Substitute (given values)

  2. Example • A sample of an ideal gas is held at 110 kPa within 15 liters volume. Its temperature is 300o Kelvin. How many moles of the gas are in the sample?

  3. Given • What quantities are provided in the problem statement with a value? • Pressure = 110 kPa • Volume = 15 Liters • Temperature = 300 Kelvin

  4. Unknowns • Quantity of gas, number of moles.

  5. Picture

  6. Principle • What is the principle you can use to describe the situation portrayed? • Ideal Gas Behavior

  7. Equation • What equation do you know, or you can find, that quantifies a relationship between the givens and unknowns? • Ideal gas law • PV=nRT • P=Pressure, V=volume, n=number of moles, R=ideal gas constant, T= temperature in degrees Kelvin

  8. Solve • Algebra first • you’ll make less math/calculator mistakes • you can retrace your work after to double check it. • PV=nRT; n=PV/RT

  9. Substitute • Givens explicitly provided in the problem statement, and some values, such as constants that you may need to look up.

  10. May need to convert! • R=0.08206 (Latm/mol K)(101.3 kPa/atm) =8.31 kPaL/mol K

  11. Kinematics Equations • v = vo + at • x=x0+vot+½ at2 • v2 = vo2 + 2aDx • Dx = ½ (vo+ v)t v=velocity a=acceleration(constant) x=position t=time subscript 0 means initital

  12. Now you try • A block slides down a ramp. At the 10 cm mark its velocity is 5 cm/s, after 30 more cm, its velocity has increased to 15 cm/sec. Assuming uniform acceleration, what is the value of the acceleration?

  13. Given • What quantities are provided in the problem statement with a value? • x0 = 0.10 m • Dx= 0.30 m • vo= 0.05 m/sec • vf = 0.15 m/sec

  14. Unknowns • Acceleration down ramp

  15. Picture

  16. Principle • What is the principle you can use to describe the situation as portrayed? • Kinematics, motion in one dimension

  17. Equation • Pick one that has your knowns and the quantity you need to find v2 = vo2 + 2aDx

  18. Solve • Algebra first • you’ll make less math/calculator mistakes • you can retrace your work after to double check it. v2 = vo2 + 2aDx; a=(v2-v02)/2Dx

  19. Substitute • Givens explicitly provided in the problem statement, and some values, such as constants that you may need to look up.

More Related