Study Guide - Engineering Dynamics | ENGR 251, Assignments of Engineering

Download Study Guide - Engineering Dynamics | ENGR 251 and more Assignments Engineering in PDF only on Docsity! Engineering 251 Instructions for Weekly Assignments Online Submission Only • Blackboard is often down for maintenance. It usually comes back up within 15 minutes. Make sure to account for this and leave yourself extra time. • Blackboard default dates and time are ET, not PT, so change your setting! • Unless otherwise stated, all assignments are open book and open notes • You may consult with other students on the assignments on the class discussion board. • You must write up your work independently. Make sure it adheres to the standards stated in the syllabus. • All students may hand in assignments in person either in class or office hours (right after class.) • Students who satisfactorily submitted part 2 of assignment 0 online may also submit assignments online by uploading your files through the assignment tool. Do not email me the file unless the Blackboard site is down. And if you must email your file, mail it to [email protected] not through Blackboard nor cuesta.edu email account. • Assignments submitted online are due at 9am on the due dates, with a cutoff at 11am with up to a point off. Leave yourself extra time to upload your file. Blackboard server connection can be slow and intermittent even if you have fast connection. • The assignment solutions will be posted by 11am, so no work will be accepted after that time. • To submit an assignment electronically, scan in your handwritten work and save it as a pdf or jpeg file only. If you don't have one, the Hi Tech Computer Lab on campus has several scanners for students use. • Here are some scanning tips: • Scan file in grayscale (or color), not black and white. Black and white scans are difficult to read. • Often, you'll have to do some image manipulation after scanning. Adjust the image so that the white background really is white instead of gray, and the darkest text is black and easily readable. • The resolution of the scanned image should be between 100 - 150 ppi and easily readable without being larger than necessary. If you view the image at 100% it should not be wider than the screen. (This point is only applicable to jpeg format.) • Crop your image cleanly. Make sure you don't cut off any written work. On the other hand, don't leave empty spaces around the image. It makes it difficult to read. • Make sure to rotate your image so that it's the right side up. • The filename convention to use for this and future assignments is "a#LastnameI.jpg" (or "a#LastnameI.pdf" if you're using .pdf format) where: # is the assignment number, Lastname is your last name, I is your initial For example, my submission for the 3rd assignment will be called a3RidgelyP.jpg. If there are more than one page, save as one multi-page pdf file or add the page number at the end of the filename before the extension, i.e., a4RidgelyP2.jpg. • Points will be taken off assignments that are in the wrong file format, have the wrong filename, or do not meet any of the above guidelines. If you have had your points taken off for the same thing a few times, you will receive zero on your future assignments until you fixed it. • After you've submitted an assignment, check to make sure it's listed under the “submitted” tab. • After an assignment has been graded, it will be listed under the "graded" tab on the assignment tool. Click on the assignment to view comments I've made about your work. It is important to do this so you learn and don't make the same mistakes repeatedly. If you handed in the assignment in person, the assignment, along with any comments, will be returned to you at the next meeting. Engr 251 Dynamics Assignment 0 Note that this assignment does not carry any grade points, but you must complete both parts to ensure your space in the class. Online students: the due date for this assignment is Monday 6/15 at 9am or 24 hours after you have been notified about your Blackboard access, whichever is later. However, assignment 1 is also due 6/15 at 9am so I highly recommend you turn in this assignment ASAP so that there's enough time for feedback. Hybrid students: the due date for this assignment is Monday 6/15 at 8pm or 24 hrs after you have been notified about your Blackboard access. You may turn in part 2 in person in Wednesday class only if you're going to turn in all future assignments in class. There are two parts to this assignment: 1) Post a message introducing yourself on the Blackboard discussion board (as a reply to the "Assignment 0 - Introduction" thread in the "General" topic). Include the name you'd like to be called, your major or intended major and three things are yourself that's unusual, interesting or that you want people to know. 2) Answer the questions below. Scan according to the assignment instructions (at a resolution of 100-150 ppi, crop out the empty spaces around the page and make sure it is easily readable and not upside down.) Save and name the file according to the assignment instructions then submit it through the Blackboard assignment tool. Note that the point of this assignment is to make sure you know how to scan and submit future assignments. As a result, you may not type up the answer instead of scanning it, nor are you allowed to submit it via email or in person instead of through the assignment tool (exception: you may submit it in person only if you will submit ALL your future assignments in class.). If your submission contains any incorrect answers, it will be sent back to you to rework until they're all correct so make sure to check back. a) What are the differences between homework and assignments? b) Where are the announcements? How do you make sure you don't miss any? Where can you find archived announcements? c) What are ways you could contact me? d) Where can you find comments on your graded assignment to see why you got points taken off? e) Do you have the correct the time zone in your Blackboard settings? f) Have you made sure you receive any future emails I may send you either through Blackboard or your my.cuesta.edu email account? Engr 251 Dynamics Assignment 3 The two 100-lb blocks are released from rest. The static and dynamic coefficient of friction  = 0.1 at all contacting surfaces. (a) What is the acceleration aA of block A as a function of the acceleration aB of block B? (hint: If block B moves the distance sB to the right, how far does block A move? Watch your signs.) (b) Determine the actual accelerations of the blocks. (c) How long does it take block A to fall 1 ft? Engr 251 Dynamics Assignment 4 The 1/4-lb slider A is pushed along the circular bar by the slotted bar. The circular bar lies in the horizontal plane. The angular position of the slotted bar is  = 10t2 rad. At t = 0.2s, determine (a) the horizontal force exerted on A by the circular bar; and (b) the horizontal force exerted on A by the slotted bar. (Hints: First show that r = 4cos. You will need to apply chain rule when finding ṙ and r̈ . Also, note that the force from the circular bar is not in the radial direction.) Engr 251 Dynamics Assignment 5 The 5-lb collar starts from rest at A and slides along the smooth semicircular bar. The spring constant is k = 100 lb/ft, and the unstretched length of the spring is 1 ft. What is the force that the bar exerts on the collar at B? Engr 251 Dynamics Assignment 8 The horizontal member ADE supporting the scoop is stationary. If the link BD is rotating in the clockwise direction at 1 rad/s, what is the angular velocity of the scoop? Engr 251 Dynamics Assignment 9 The ends of the bar AB are confined to move along the paths shown. At a given instant, A has a velocity of 8 ft/s and an acceleration of 3 ft/s2 as shown. Determine the angular velocity and angular acceleration of AB at this instant. Engr 251 Dynamics Assignment 10 The disk rolls on the plane surface with a constant counterclockwise angular velocity of 10 rad/s. Bar AB slides on the surface of the disk at A. Determine the angular velocity and angular acceleration of bar AB. Engr 251 Dynamics Assignment 13 The 2-kg bar is 1 m in length. It rotates in the horizontal plane about the smooth pin. The 6-kg collar A slides on the smooth bar. The unstretched length of the spring is 0.2m, and the spring constant is k = 10 N/m. At the instant shown, the angular velocity of the bar is ω0 = 2 rad/s, the distance from the pin to the collar is r = 0.6 m, and the radial velocity of the collar is zero. Neglect the moment of inertia of the collar about its mass center. When the distance from the pin to the collar is r = 0.8 m, (a) determine the bar's angular velocity; and (b) calculate the collar's radial velocity. Engr 251 Dynamics Assignment 14 The uniform 40-lb disk rotates in the vertical plane about O. Immediately before it hits the inclined surface at A, its angular velocity is ω1 = 4 rad/s CCW. Just after the impact, the angular velocity of the disk is ω2 = 1.5 rad/s CW. Determine the magnitude of the impulse that acted during the impact on (a) the surface at A; and (b) the pin at O. Neglect friction. Engr 251 Dynamics Assignment 15 The collar and clevis A are given a constant upward velocity of 12 in./sec for an interval of motion and cause the ball end of the bar to slide in the radial slot in the rotating disk. The disk turns at the constant rate of 2 rad/sec in the direction shown. When the bar passes the position for which z = 3 in, calculate (a) velocity and acceleration of end B relative to the disk, (b) the angular velocity and acceleration of the bar relative to a fixed coordinates, (c) velocity and acceleration of end B relative to a fixed coordinates.