exam 1 sp08 solution - ENSC 2123 Exam 1 Spring 2008(25...

Info icon This preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ENSC 2123 Exam 1 Spring 2008 (25 points) A rocket powered sled starts from rest and accelerates at: a = 30 + 2t m/sz, until it reaches a speed of 200 m/s. At that point, it releases a parachute brake, and decelerates at: = -0.3v m/s2. a) Determine the time required to reach 200 m/s during the acceleration phase. ‘U 012%? ~5 {éohfzfolv’y fiéo+2£>0ié =[0/D’ .1 f 0U . L V 30é+f 54/: U/g/ % U230f+1£ FEM 02 200 3 200 ‘2 30t+f1 or {73-30% “2,00 :0 Clam/”0°45 69w 2 z —— 30 :- W ' 657 b) Determine the distance required to reach 200 m/s during the acceleratiorzphase. S t: (go'év‘fljo‘l‘é 0) Determine the distance required to come to a stop in the during the deceéeration phase. = ‘- ‘V’ g i: Hal/7f d5 '2 27d a 0‘2 0:30! 8f %a(v~) 6 a 3 0h; «’2’; Oi ‘U 2 : Zr “:“3‘ S _O.'3/U’ 0‘2 013 Zoé Co /6 2. (25 points) Ifthe Club the golfer is using gives the ball an frfiial angle of (90 2 50 degrees, determine the initial velocity v0 that will cause the ball to land in the hole at the base of the flag pole. from (I) C); 2 .3; M0 w $0530! “7!" Q} 3 ,, (65506 ‘f (505300 0.23.23» {2/ fi[email protected]/¥Z€5 a [5/24 (0:55 32”?— 022 32.7 fl/S Name /é / (25 points) The coefficients of friction between the box A and the bed of the utility vehicle are us I 0.4 and pk = 0.36. The vehicle is initially traveling up the hill at a speed of 20 ft/s. The hill angle is 6’: 15 degrees. If the driver carefully applies the brakes, determine the smallest stopping distance for which the load will not slide on the bed. ,o fifth 50x3 ZF=MQ =0 \R (3 // ‘3 M -=— ”I'M-JO '60 I: M3 6059 N mycosé § éfi; '3 MQLX, i , \é ~35~m35m©=max g , “5% I’d/e 60/ {2 ”as/V 5' fl: my€@[email protected] \h 5 ) 3 N0 1 n/ M v \Q ,/ . {9/ . w//:,nuggé w,,a§/n©:/WQK 3U ‘ f, u ecceix MS/ J 03/ ’/ d 6 51.7: /./0 Q Name /(67 4. (25 points) A boy rides a skateboard on the concrete surface of an empty drainage canal described by the equation shown in the figure. He starts at y = 20 ft, and the magnitude of his velocity is approximated by the equation given below the figure. If the boy weighs 140 lbs, determine the normal force between the boy and the concrete surface when he reaches x = 15 ft. You may ignore friction and you may ignore the size of the boyJand the skateboard (treat them as one particle). Fifi/IWIHQ’V (5 720 161C N 3 9 7 «aimgCOSQ +N Oklahoma State University Engineering Science 2123 Elementary Dynamics General Definitions ds v = —— d1 dv a = w dz ads : vdv Constant Acceleration 5 2 so +v0(t—t0)+%ac(t—t0)2 v 2 V0 +ac(t—t0) 112 : v3 + 26h- (s — 50) Cartesian Coordinates r=xi+yj+zk v:)'ci+yj+z’k aziéi+j§j+2k Normal and Tangential Components Equation Sheet Cylindrical Coordinates r=rer+ze: rzfer +r6e9 +z‘e: Relative Motion (Translating Axes) r3 :rA +rB/A VB :VA +VB/A 33 Z 3A + aB/A Kinetics ofa Particle d (mv) dt 2F 2 ma (constant mass) 2F: p [1+(y')2]“2 [r-+(r')2]“ _ -511 udzy y—f(X), y —dx, y —dx2 dr dzr : 6 I:— ”2 ' g( )’ r de’ 0192 ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern