MECH 3AA0 2

pdf

School

Auburn University *

*We aren’t endorsed by this school

Course

3AA0

Subject

Mechanical Engineering

Date

Apr 3, 2024

Type

pdf

Pages

Uploaded by AmbassadorMusic3308

Question 1 1pts A particle having an initial velocity of 30 m/s experiences an acceleration as shown. Acc(t) =50—15-t [2] ra V(t,) =30 [2] Find the distance the particle travels [m] after 20 seconds. Question 2 1pts A 15 kg block is moving along a horizontal surface at an initial velocity of 12 m/s. Friction between the surface and the block causes the block to come to a complete rest in 4 seconds. Determine the value of the kinetic coefficient of friction . Velocity (mis) time (s) Question 3 1pts Find the energy (work) needed (in Btu) to lift a 320 Ib,, from the ground up to the roof of a building that is 45 ft high.

Question 4 1pts Two 6 kg masses are travelling toward each other in a straight line, each at a velocity of 15 m/s. After colliding, each mass is ricocheted 180 degrees in the exact opposite direction it was travelling prior to the collision. Find the speed (magnitude of velocity) of masses after the collision if the coefficient of restitution of the collision is 0.80. &= 0.80 AFTER COLLISION Note, since both masses are the same and the initial speeds are identical, the masses will also have the same speed after the collision, travelling in opposite directions of their initial velocity. Question 5 1pts Points A and B are on a rigid body that has an angular velocity, (w) of 5k rad/s. The position of B relative to A'is (rg/s) 10i + 10j cm. The velocity of A relative to a global coordinate system (V) is 10i + 10j cm/s. Find the velocity vector (cm/s) of B relative to the global coordinate system? Global Coordinates © 20i +60j cm/s © ~20i+ 60j cm/s © -40i + 60j cm/s © -40i - 60 cm/s © 40i +60j cm/s

Question 6 1pts Crank arm OA is initially at rest and ideally pinned at point O. The initial angle the crank arm makes with the horizontal is 6 = 30°, its length AOis 1.0 m, its mass is 5.0 kg. The mass moment inertia about the pin joint (point O) is 1.67 kgm2. The crank arm is released and and acted on by gravity. What is the magnitude of the angular acceleration (rad/s?) at the moment the crank arm is released ? Question 7 1pts Determine the axial stress (kPa) that a 3.0 meter long steel I-Beam would experience given a 30°C increase in temperature if the |-Beam is fixed at both ends and cannot expand or contract. The I-Beam is made from steel and has a cross-sectional area of 0.001964 m2. Use the Material Properties Table (page 89 of 9th ed. of the NCEES Handbook). Question 8 1pts Asolid 5 meter long circular shaft with a diameter of 5 cm has an applied torque of 300 N-m. Under this torsional the shaft is observed to twist 5.5 degrees. Using the Material Properties Table (page 89 of the 9th ed. of your NCEES Handbook), determine the most likely material maximum the shaft is made from. O Copper or Bronze O steel O Aluminum O Magnesium O Brass or Cast Iron

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Question 9 1pts A cantilevered beam is loaded with a uniformly distributed load as shown below. If wy = 1500 Ib¢/ft, what is the value of the moment (ft-Ibg) at x = 2 ft? For your answer use CCW as a (+) positive moment. X (ft) 0 O -1000 O 1500 0 750 © 1000 O -750 Question 10 1pts A wide-flange beam (I-beam) is subjected to a maximum moment of 3000 ft-Ib. The beam’s section has a second moment of inertia about its centroid, 1, = 25 in%. The beam has an overall height of 3”. Determine the magnitude (psi) of the maximum normal stress in the beam.

Question 11 1pts Consider a Principle Plane stress state where o, is at +3 MPa (tension), o, is at -3 MPa (compression), and the in-plane shear 7, is at 4 MPa. Find the resulting maximum in-plane compression (in MPa) for the given state. Enter your value as x.x, where the negative sign is implied since it is compression. Yy Ox Ox Oy Question 12 1pts A 4.0 meter long (L) cantilever steel beam (E=200 GPa) is loaded at its mid-span (a = 2.0 meters) with a concentrated force (P) of 3.0 kN. The beam’s section has a moment of inertia about its centroid, I, = 30.0E-6 m*. Determine the magnitude of the maximum deflection (in units of mm) of the beam. Question 13 1pts Find the mass-specific internal energy (in kJ/kg) for Steam at 400 kPa having a specific-volume of 0.7726 m3/kg.

Question 14 1pts Arigid tank having a volume of 1.0 m? contains super-heated steam at a pressure of 400 kPa and temperature of 250°C. Heat is added at constant pressure until the volume doubles. Assuming there are no other heat or work interactions, find the temperature of the steam (in °C) after the volume doubles. Question 15 1pts An ideal gas turbine operates using air (k=1.4) coming at 375°C and 300 kPa. Find the exit pressure (kPa) if the air exits at 125 °C. Assume the air behaves ideally, properties are constant, and the turbine operates isentropically. Question 16 1pts A 10 kg block of Aluminum initially at 225°C cools in ambient air at 25°C. Find the total increase in entropy for the aluminum block + surroundings (kJ/K) if the aluminum cools down to the ambient air temperature. Note, the cooling process removes 1800 kJ from the aluminum block. Question 17 1pts An Otto cycle operating with air has a volumetric ratio (:’4) of 14:1. Find the rate of heat addition necessary (in kW) if the engine is producing 325 horsepower of net work output. Assume the cold air standard with k=1.4. Question 18 1pts A refrigeration system is removing 15 kW from a refrigerated space (Q,) being held at -5°C (T,). The refrigeration system is rejecting 18.5 kW of heat (Qy) to the outside ambient air at 35°C (TH). Find the C.O.P. (coefficient of performance) for this system under these conditions. 0429 0529 067 0 0130 077 Question 19 1pts A mixture of nitrogen and argon are mixed such that there are 2 moles of argon for every mole of nitrogen. The gas mixture is contained ina 1 m3 vessel and is at standard temperature and pressure (STP) conditions, 25 °C and 100 kPa. Find the mass fraction (entered as xx.x) of the nitrogen in the mixture assuming the gases behave ideally.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Question 20 1pts Using the Psychometric chart, find the wet bulb temperature (in °C) for moist atmospheric air at a dry-bulb temperature 25°C and a relative humidity of 30%. Question 21 1pts A submarine is designed to withstand an external pressure of 6.0 MPa. If the submarine is operating in salt water with a density of 1025 Kg/m®, what is the maximum operating depth (meters)? Question 22 1pts Aleaf blower draws in air at a rate of 25 m®/min with a negligible velocity. The blower discharges the air out of its nozzle at a velocity of 200 km/hr . If the air has a density of 1.206 kg/m?, find the force (N) the discharging air imparts back onto the leaf blower 0233 0124 0279 0307 0155 J Question 23 1pts Water is flowing through a straight section of pipe. The flow is in the fully turbulent range. If the flow rate is doubled, by what factor will the pressure drop in the pipe change compared to the original pressure drop? 0os o2 04 © 0.707 O 1414 Question 24 1pts Oil at a velocity of 30 m/s flows along the length of one side of a flat plate that is 1 meter long and 3 meters wide. Determine the resulting drag force (in N) on the plate. The oil has a specific gravity of 0.88 and a dynamic viscosity of 0.08016 Pa-s. For the density of water use 998.2 kg/md.

Question 25 1pts Air with a density of 1.20 kg/m? flows in a duct under ideal steady & incompressible conditions. At one point in the duct, the pressure is 100 kPa and the velocity is 45 m/s. Down stream the pressure is 99.7 kPa. Determine the velocity (m/s) at the downstream location. Question 26 1pts Find the cross-product C = A x B,where A = (1,0,—1)and B = (—1,1,0). Using (4, j, k) vector notation, A and B can also be represented as follows. A=i-k B=—i+tj 0 C=(1,1,0) 0C=(1,-11) 0 C=(-1,1,-1) 0C=(1,1,1) O No answer text provided. 0 C=(-1,0,0) Question 27 1pts Find the angle between vectors A = (1,0, —1) and B = (—1,1,0) in degrees. Using (4, j, k) vector notation, Aand B can also be represented as follows. A=i—k B=—i+j

Question 28 1pts What is the value of A at the end of this loop? A=20; n=0; while A>8 A=A-2; n=n+l; O Novalue , infinite loop 020 o6 os 04 Question 29 What is the value for C that is printed to the screen when this MATLAB script is executed? A=6; B=8; ifA==10 | B~= Cc- elseif A==6 & B== C=2; elseif A== C=3; else C=4; end C

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Question 30 1 pts The values of an unknown function at five equally-spaced points are given in the Table Below. Using the Trapezoidal Rule (page 41 in the 9th ed. of the NCEES Handbook) numerically integrate the function from 0.0 to 0.8 using the five values in the Table. Note that Az = 0.2. x-value 0.00 0.20 0.40 0.60 0.80 f(x) 1.00 0.961 0.852 0.698 0.527