EF 151 Exam #2 - Fall, 2017 Page 1 Copy 1 Name: Section: Before the Exam Starts: Sit in assigned seat; failure to sit in assigned seat results in a 0 for the exam. Put name and section on your exam. Put seating label on your equation sheet. Do not open the test until you are told to do so. Instructions and Guidelines for the Exam: On the first page, completely color in the dot for your chosen answers. Write your final answers in the boxes provided Assume 3 significant figures for all given numbers unless otherwise stated Show all of your work no work, no credit Include units for all answers and directions for all vectors At the end of the Exam: If you finish with less than 5 minutes remaining, please stay seated until the exam is over. Stop work immediately when time is over; working after time is over results in an automatic point deduction Turn in your equation sheet with your examination. Pass exams to the aisle; stay seated until all exams are collected. Lab Time 8:10 9:40 11:10 12:40 2:10 3:40 Lab Room 102 212 216 217 218 A102 Justin B102 Chris C102 Justin D102 Rekesh E102 Rekesh F102 Rekesh A212 Daniel B212 Daniel C212 Daniel A216 Andrea B216 Andrea C216 Andrea D216 Heather E216 Heather F216 Heather A217 Landon B217 Landon C217 Landon D217 Tayler E217 Tayler F217 Tayler A218 Matthew B218 Matthew C218 Matthew D218 Chris E218 Justin
EF 151 Exam #2 - Fall, 2017 Page 2 Copy 1 This page intentionally left blank.
EF 151 Exam #2 - Fall, 2017 Page 3 Copy 1 Name: Section: 1. ( 2 pts ) Enter your EXAM ID from your seating label. If you don t know your exam ID, enter 000. 0 1 2 3 4 5 6 7 8 9 Digit #1 Digit #2 Digit #3 2. ( 2 pt ) What is NOT true for projectile motion? Neglect air resistance Acceleration due to gravity Vertical motion is dependent on horizontal motion Acceleration only has a vertical component 3. ( 2 pt ) Newton s 1 st Law says if no is applied, then an object is. Acceleration; A Vector Net Force; Constant Velocity Air Resistance; In Projectile Motion 4. ( 2 pt ) The trajectory equation is a function of all of the following variables EXCEPT: xo vo t yo 5. ( 2 pt ) An astronaut in space is weightless, which means she has a mass of zero. True False Depends on gravity 6. ( 2 pt ) An object is sitting on the floor. A push force is applied but the object is not moving. The appropriate way to calculate friction in this case is: Based on the FBD F = s*n F = k*n 7. (2 pt ) Amos, the chihuahua, weighs 49 N on earth. What is Amos s mass on the Saturn (g = 11.08 m/s 2 )? 49 N 49 kg 5 N 5 kg 55.3 N 55.3 kg
EF 151 Exam #2 - Fall, 2017 Page 4 Copy 1 8. (2 pt ) What is the correct form of the relative velocity equation? v b/a = v a/g + v b/g v b/g = v b/a v a/g v b/g = v b/a + v a/g 9. (2 pt ) Which of Newton s Laws tells us that if you push on a brick wall, the brick wall pushes equally back on you? First Second Third 10. (2 pt ) True or False: When drawing a Free Body Diagram, acceleration vectors should be included on the FBD. True False 11. (2 pt ) A football is thrown at 90 ft/s at an angle of 30 CCW the +x-axis and travels 218 ft before hitting the ground. How far would a football coach travel if thrown under the same conditions? Football Coach < Football Football Coach = Football Football Coach > Football 12. (2 pt ) Which is a scalar value? Force Mass Acceleration 13. ( 12 pt ) A cart with wheels that roll freely (no friction) is pushed up a hill with force, P. If the cart accelerates at 1.2 ft/s 2, what is the weight of the cart? (FBD = KD required) P = 22 lb 19 o
EF 151 Exam #2 - Fall, 2017 Page 5 Copy 1 14. ( 16 pt ) A tennis ball is shot into the air at a speed of 17 ft/s at a certain angle and some distance above the ground. The tennis ball lands 17.4 feet away after 1.9 seconds. At what height was the tennis ball launched? 15. ( 16 pt ) Dr. McCord wants to take a trip to Mount Rushmore in Rapid City, SD over Fall Break. Ground distance between Knoxville and Rapid City, SD is 1440 miles at a heading of 40 o N of W. If the plane s top airspeed is 500 mph and there is a wind speed of 47 mph at a heading of 17 o W of S, how fast can she make it to Rapid City? (To get full credit, a fully labeled vector diagram is required.)
EF 151 Exam #2 - Fall, 2017 Page 6 Copy 1 16. ( 16 pt ) A tractor drags a box across the ground. The tractor has a tractive force of 275 lb. The tractor has a weight of 975 lb. The box has a weight of 325 lb. What is the force in the coupling between the tractor and the box? (2 FBD = KD s required) Box W = 325 lb Tractor W = 975 lb s = 0.8, k = 0.55 17. ( 16 pt ) Find the minimum force P to keep the block from sliding down the incline. (FBD = KD required) μs = 0.60 k = 0.22 37 P