W09 Physics Exam 2

U0 wIB TR b . 0v SR L ESTR SN IR Rt S S \‘::‘..‘\‘,)frn. i ;}‘ ::,. 3 ;f-lf&'*&{ R e Principles of Physics Exam 2 Document 1. I understand that I have agreed to follow the Honor Code to be able to receive the blessings of gaining an education while I am a student at BYU-Idaho. I will not cheat or do anything that would cause me to be dishonest in any way. ‘@. Iagree b. I disagree The multiple choice problems are each worth 3 points, 2 points for the answer and 1 for the explanation and/or work. All other problems are worth the points noted, with 2 points for the answer and the rest for the work. 2. Joe and Bill are playing tug-o-war. Joe is pulling with a force of 200 N. Bill is simply hanging onto the rope. Neither person is moving. What is the tension of the rope? . a. 400N b. 300N c. ON @ 200N 3. An object is moving to the right in a straight line. The net force acting on the object is also directed to the right, but the magnitude of the force is decreasing with time. The object will @/&— a. continue to move to the right, with its speed decreasing with time. continue to move to the right with a constant speed. c. continue to move to the right, with its speed increasing with time. L"MF_'L ¥ d. stop and then begin moving to the left. -@%V“f“ a(eleva Yim P VY an-caJ\M Eo s = (av\i*‘"‘.}-v 4. Two unequal masses M and m are connected by a light cord passing over a pulley of negligible mass. When released, the system accelerates. Friction is negligible. D omoe BT B m _ Ny ¥ flClVLg -m) = Ma off: Which figure below gives the correct free-body force diagrams for the two masses in this moving system? i a. : b. ® d.

Use this graph for the next two questions. . | i | _al 3 a 23| 23 g | AU A\ - gr i Vo it e _ pototd 74093 0. - 0 Posttion (meters) _y 5. At the 2-meter position, what is the direction of the force? In the positive direction (to the right) b. In the negative direction (to the left) c. There is no force at this point. 6. At which meter-mark is there most nearly a stable equilibrium point in the potential energy graph? e e ot a- 1 G A . B . Tr/ ¢ 5 Y\ear/ at %w\a, Yo RE ¥ ;/\(5}35 e B A L o Ty s .’{' - h‘\(‘ | g: g '}V\mra =0, Th's i ou ZAddl brivlfi)\?’flh‘,'- N f. 6 a P'resgvvté k £ & E\M;\l:/‘qb‘{/ 2. The force a spring exerts on a body is a conservative force because ’ : %{wcg I/fijd* i a. a spring always exerts a force opposite to the displacement of the body. b. a spring always exerts a force parallel to the displacement of the body. _ c. the work a spring does on a body is equal for compressions and extensions of equal _rnagmtude. the work a spring does on a body is equal and opposite for compressions and extensions of equal magnitude. o N e. the net work a spring does on a body is zero when the body returns to its initial position. 8. A large truck collides head-on with a cyclist. During the collision, /\/e w-}g»n'g 3 rd l’O\V rts a smaller amount of force on the cyclist than the cyclist exerts on the fiqvo\ 0\\? opget '}e oo Hen the truck exe Elr;%cg:uck exerts a greater amount of force on the cyclist than the cyclist exerts on the truck. al b . . ; the truck. truck exerts the same amount of force on the g:yclnst as the cyclist exerts on % tt:flg truck exerts a force on the cyclist, but the cyclist exerts no force onto the truck. - mirror of a car. A ball is hanging on the other end of the string. et o e o sts gives all of the forces ~ ¥ T\ gt 9. A string is attach ] the The car isgdriving around in a circle at a constant speed. Which of the fpl_lgmng li directly acting on the ball? . a. tension, gravity, and the centripetal force b. tension: gravity: the centripetal force, and friction c. tension @ tension and gravity

The figure shows a blpck of mass m resting on a 20.0° slope. The block has coefficients of friction ps = 0.55 and py = 0.45 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. w Ui =015 M99 = SinBmg~ N s) = O W¢ = 0SS W‘?fi" S g et Mo A T= §n@msg - W‘lg S 51\16’%& +Cos w}qufi Mg A F{n‘c =NV /V; 6059"‘4,? M?fi:— mi(g?hég ‘!’C(&gv ‘:; 14. What is the minimum mass m that will stick and not slip? (7 points) W24 iy I6mo4sovy) L A @9 Kvs&dfg‘ifl WA 2152 A N9 K {4 ; Z Iy 15. What is the acceleration of the hanging mass if the mass m=1.9 kg? (6 I 29 - 5 y\@M}@ )= Nug = (\h\i-flm) a KZ'U @@;Q —Sy@o)t) 4(?59”?{!'-‘?}‘»“;; pOBE T 4 M, g —SinGwy g — %@M}&VK S - : i - VT —— ' , !ol +Z'” W W5 % s d4=|l3zu y 16. If m=}\.9 k<_t; ra]md tthhe hangigg T:ss stsr)ts 0.54 m above the ground, what is the speed of the hanging mass when it hits the grouna: points « - N /‘\qu, V= 0%Ys \[{:}; \Iil-t'la,AY az smsr Iz 114 V42 = ot + 20979 (054 r AN - 2 L Ir | VEx1.2 % Or=a5y,, (2 Mg Ve 12160 17. Continuing where 16. left off, if m=1.9 kg, how long (time) after the hanging mass hits the ground does the mass m slide up the slope before stopping? (6 points) P M Ot [ 28w Y Vit ade g Pt P b g U= | 8RS0 Wt = o 4 ; 3 / . ._y . /— ,\ /"\, ‘%) . B Tl VE-W A, VYo Mz V- BT g 7 AL L, 0=l 3N ve W}:\Vsi .Afi,.—v 3 (4 Boope st ‘?cflc\c W)

A tetherball is on a 2.1 m string which makes an angle of 44° in a horizontal plane. The mass of the ball is 1.3 kg. y with the vertical as it moves around the pole 18. What is the ball’s speed? (8 points) | m @) T80, m)srfi = zQ $) i O) n @ %)" | /S\‘V\g:'—j_—f 21Ty Sl o A) T= v (QZ T ( = 9_ Ot [ CO"@&)(H) W\(v) - =y S ; =y (s — Lsin6 LLOZ AN S 19. How long does it take the ball to make one revolution? (4 points) - V /1;)/(‘&)\'@ 13, % & V=371 Ve L8y '=L4sne & « (= 28 9 My ~r Yey — W=Z:706 "% . rod ec = 2. Ese] iageliy 2017 X You want to build a sculpture that incorporates the ideas you ve learned in your physics class to go in your entryway. A marble (mass=4.99) is shot up a tube by a spring (k=20.0N/m) to the top of a roller coaster. Water flows through the tube so it lsb All heights are measured from the top of the compressed spring. ME[N'S \hh»woc“ |§ %0/ \ FE§ - h@zq > , hoboch W=t Ay R S hoeB T Deeamg, /\/“ PE, = RE A+ PE, PE 20. How rpuch must th_e spri%g be compressed for the marble to have a speed of 1.3m/s at the top of the hump (point C)? (6 points) % ’ 3% P k): j— )Orc \| ' =" 0 MOYV,O@ ”LK@X) gm(me&%c Th SP“@NV5+ he o wpcd 4)(2» 2m (QM\ +9\1¢ by 4:00m oo aspeod "‘““")“\- ' d-? |3 W/§pt Th )LdpaF y N Q(O«OGH \ 2 . = (132 42 2 €00 i =2 Z’Zflfif zm__,, X OOO 637 ,yf] e X, O'QHO@HM ,OM OY‘O ’LW\ o\{\l'{ ('/C/\N\ \