Glossary - Physics

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a WOW Lab Indoor Rockets Glossary - Physics acceleration - the rate at which an object’s velocity mechanical energy - the sum of the kinetic energy changes with time. and the potential energy present in a system. aerodynamic force - a resistive force exerted on an momentum - the product of the mass of an object object by the gas in which it is immersed whenever and its velocity. the object moves relative to the gas. The aerodynamic force is usually separated into drag and lift. mechanical force - a force that can only be exerted on an object if the object is in physical contact with drag - the component of the aerodynamic force that the origin of the force. runs parallel to the direction of relative motion. potential energy - the stored energy that an object field force - a force that can be exerted on an object possesses because of its position with respect to even when the object is not in contact with the other objects. source of the force. pressure - the force exerted per unit area. force - an influence that causes an object to change its rate of motion. scalar - a quantity that possesses magnitude, without regard for direction. free fall - motion of an object under the influence of gravity only. speed - the time rate at which distance is covered by a moving object. friction - the resistance to motion on a surface. thrust - a force exerted on an object by its propulsion gravitational force - the force of attraction between system. It is derived from Newton’s Third Law of all masses in the universe. In everyday life, this is what Motion. gives weight to objects which have a mass, causing them to fall to the ground when dropped. vector - a quantity that has both magnitude and direction. kinetic energy - energy possessed by an object due to its motion. velocity - distance travelled per unit time. lift - the component of the aerodynamic force that runs perpendicular to the direction of relative motion..

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Glossary Physics (I-Introduction)
1 Glossary Physics (I-introduction) - Efficiency: The percent of the work put into a machine that is converted into useful work output; = work done / energy used [-]. = eta In machines: The work output of any machine cannot exceed the work input (<=100%); in an ideal machine, where no energy is transformed into heat: work(input) = work(output), =100%. Energy: The property of a system that enables it to do work. Conservation o. E.: Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes. Equilibrium: The state of an object when not acted upon by a net force or net torque; an object in equilibrium may be at rest or moving at uniform velocity - not accelerating. Mechanical E.: The state of an object or system of objects for which any impressed forces cancels to zero and no acceleration occurs. Dynamic E.: Object is moving without experiencing acceleration. Static E.: Object is at rest.F Force: The influence that can cause an object to be accelerated or retarded; is always in the direction of the net force, hence a vector quantity; the four elementary forces are: Electromagnetic F.: Is an attraction or repulsion G, gravit. const.6.672E-11[Nm2/kg2] between electric charges: d, distance [m] 2 2 2 2 F = 1/(40) (q1q2/d ) [(CC/m )(Nm /C )] = [N] m,M, mass [kg] Gravitational F.: Is a mutual attraction between all masses: q, charge [As] [C] 2 2 2 2 F = GmM/d [Nm /kg kg 1/m ] = [N] 0, dielectric constant Strong F.: (nuclear force) Acts within the nuclei of atoms: 8.854E-12 [C2/Nm2] [F/m] 2 2 2 2 2 F = 1/(40) (e /d ) [(CC/m )(Nm /C )] = [N] , 3.14 [-] Weak F.: Manifests itself in special reactions among elementary e, 1.60210 E-19 [As] [C] particles, such as the reaction that occur in radioactive decay.
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Drag Force Calculation
DRAG FORCE CALCULATION “Drag is the component of force on a body acting parallel to the direction of relative motion.” [1] This can occur between two differing fluids or between a fluid and a solid. In this lab, the drag force will be explored between a fluid, air, and a solid shape. Drag force is a function of shape geometry, velocity of the moving fluid over a stationary shape, and the fluid properties density and viscosity. It can be calculated using the following equation, ퟏ 푭 = 흆푨푪 푽ퟐ 푫 ퟐ 푫 Equation 1: Drag force equation using total profile where ρ is density determined from Table A.9 or A.10 in your textbook A is the frontal area of the submerged object CD is the drag coefficient determined from Table 1 V is the free-stream velocity measured during the lab Table 1: Known drag coefficients for various shapes Body Status Shape CD Square Rod Sharp Corner 2.2 Circular Rod 0.3 Concave Face 1.2 Semicircular Rod Flat Face 1.7 The drag force of an object can also be calculated by applying the conservation of momentum equation for your stationary object. 휕 퐹⃗ = ∫ 푉⃗⃗ 휌푑∀ + ∫ 푉⃗⃗휌푉⃗⃗ ∙ 푑퐴⃗ 휕푡 퐶푉 퐶푆 Assuming steady flow, the equation reduces to 퐹⃗ = ∫ 푉⃗⃗휌푉⃗⃗ ∙ 푑퐴⃗ 퐶푆 The following frontal view of the duct is shown below. Integrating the velocity profile after the shape will allow calculation of drag force per unit span. Figure 1: Velocity profile after an inserted shape. Combining the previous equation with Figure 1, the following equation is obtained: 푊 퐷푓 = ∫ 휌푈푖(푈∞ − 푈푖)퐿푑푦 0 Simplifying the equation, you get: 20 퐷푓 = 휌퐿 ∑ 푈푖(푈∞ − 푈푖)훥푦 푖=1 Equation 2: Drag force equation using wake profile The pressure measurements can be converted into velocity using the Bernoulli’s equation as follows: 2Δ푃푖 푈푖 = √ 휌퐴푖푟 Be sure to remember that the manometers used are in W.C.
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Chapter 4: Immersed Body Flow [Pp
MECH 3492 Fluid Mechanics and Applications Univ. of Manitoba Fall Term, 2017 Chapter 4: Immersed Body Flow [pp. 445-459 (8e), or 374-386 (9e)] Dr. Bing-Chen Wang Dept. of Mechanical Engineering Univ. of Manitoba, Winnipeg, MB, R3T 5V6 When a viscous fluid flow passes a solid body (fully-immersed in the fluid), the body experiences a net force, F, which can be decomposed into two components: a drag force F , which is parallel to the flow direction, and • D a lift force F , which is perpendicular to the flow direction. • L The drag coefficient CD and lift coefficient CL are defined as follows: FD FL CD = 1 2 and CL = 1 2 , (112) 2 ρU A 2 ρU Ap respectively. Here, U is the free-stream velocity, A is the “wetted area” (total surface area in contact with fluid), and Ap is the “planform area” (maximum projected area of an object such as a wing). In the remainder of this section, we focus our attention on the drag forces. As discussed previously, there are two types of drag forces acting on a solid body immersed in a viscous flow: friction drag (also called “viscous drag”), due to the wall friction shear stress exerted on the • surface of a solid body; pressure drag (also called “form drag”), due to the difference in the pressure exerted on the front • and rear surfaces of a solid body. The friction drag and pressure drag on a finite immersed body are defined as FD,vis = τwdA and FD, pres = pdA , (113) ZA ZA Streamwise component respectively.
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Curriculum Overview Physics/Pre-AP 2018-2019 1St Nine Weeks
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UNIT – 4 FORCES on IMMERSED BODIES Lecture-01
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Systematic Errors in High-Precision Gravity Measurements by Light-Pulse Atom Interferometry on the Ground and in Space
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LIGO: the Search for the Gravitational Wave Sky
LIGO: The Search for the Gravitational Wave Sky • Science • LIGO status • UO in LIGO R Frey Oct 2008 1 General Relativity • Grav ity as a “fic titious f orce” Gravity can be “removed” in a special ref. frame -- free fall • Einstein took this as a clue that gravity is really caused by the structure of spacetime • Postulates of General Relativity (Einstein ca. 1915): Equivalence of inertial and gravitational mass There is no physics experiment which can distinguish between a gravitational field and an accelerating reference frame • An elevator at rest in earth’s gravity (g=9.8 m/s2) • An elevator accelerating upward with a= 9. 8 m/s2 • What this means extends special relativity to non-zero acceleration GitGravity re-dibddescribed as curva ture o f space time • A test particle (or light) in free fall follows a “straight” geodesic R Frey Oct 2008 2 General Relativity (contd) SdiiSome predictions: Gravity influences both mass and energy • e.g. bending of light in regions with gravitational field • 1919 Eddington; Gravitational lensing: Einstein Cross Many small deviations from Newtonian gravity in “weak” fields • Gravitational “redshift” (e.g. clocks on satellites are faster) • Perihelion advance of mercury • Global Positioning System would not work without GR corrections “Strong” field effects 2 • Black holes; Rs = 2GM/c Spacetime structure of universe – evolution of spacetime from Big Bang • the “bi g s tre tc h” And gravitational radiation (gravitational waves) R Frey Oct 2008 3 GWs in GR R Frey Oct 2008 4 The 4 Forces of Nature
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Albert Einstein's Key Breakthrough — Relativity
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Chapter 4: Immersed Body Flow [Pp
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Part 629 – Glossary of Landform and Geologic Terms
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Hydraulics Manual Glossary G - 3
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Gravity and Projectile Motion
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