Two Part Projectile Motion - Introductory Physics - Solved Paper, Exams of Physics

Download Two Part Projectile Motion - Introductory Physics - Solved Paper and more Exams Physics in PDF only on Docsity! FROM : FAx NOL: Mar. G? S443 2:83PM PL University of California at Berkeley Department of Physics Physics 8A, Spring 2003 Midterm 1 March 5, 2003 12 You will be given ho minutes to work this exam. No books are allowed, but you may use handwritten formulae sheet no larger than one side of an 8 1/2 by 11 sheet of paper. Your description of the physics involved in a problem is worth significantly more than any numerical answer, Show all work, and take particular care to explain what you are doing. Please use the symbols described in the problems, tell us why you're writing any new equations, and label any drawings that you make. Write your answers directly on the exam, and if you have to use the back of a shect make surc to puta note on the front. Do not use a blue book or scratch paper. vedvdt — asdvidt — xQ=xytvttl2a? Fama R=mv'sr FR=4N W=Fe PedWidt K=l2mv) U=mgh D=5Cpv? AK=K-K, AU=U-U, W=AU+AK+AEy+AE,,, en vet es Vy Vay = mrt ptt Voy wae Cectuve. | SID NUMBER: Salotic a Set 5 DISCUSSION SECTION NUMBER: : 5 DISCUSSION SECTION DATE/TIME: F 3 ‘Total ee FROM : Ca) (b) FAX NOL: Mar. @? 2083 @2:@3PM P2 1) (20points) Sliding block A block slides down a track that starts with a of a circle, and ends with a flat and level part. At the end of the truck, it hits and sticks to a stop. Notc that the ramp is free to move left and right. You can ignore friction in this problem. The mass of the block is m1, and the mass of the ramp is m2. The radius of the circular part of the ramp is R, and the Jength of the straight part is L. If you use conservation laws-to solve any part of this | L we problem, make it really clear which ones wt | you're using, and how you're applying them. ae a) After the block has stuck to the ramp, are the combined ramp & block moving to the left, to the right or stationary? b) Between the time the block started moving and the time that the block hit the stop, did the center of mass of the two objects move up or down? Did it move right or left? ©) What is the position of the block when it hits the stop? Note that the diagram as an x=0 point defined, please use that, sak mat vw tu system =O ; ph te (te LP Aya te block has stk Hou seth ee ka womnnduma 300 ee” Hayill. be itadiouang Bees oa well “Yeasts theyll be “iter x nm apal WW A cecndiog to Ht law snus of cop” . Renrce. Pur & Wo eyternal avid ow esata : ae weak Alin fou x-portion a tile pare Se Hea Rural moet t Hasan 2 Spo bat ang foe Lowse flow ao well afl FROM FAX NO. + Mar. @? 2083 Ge:g4PmM PS 3) (20 points) Two blocks Two blocks are connected by a string as shown. Friction cannot be ignored. Use m, and m, for the masses of the two blocks, and j4, and 1, for the coefficients of static and kinematic friction. ‘You can assume that m, is larger than m,, Using just the information given, determine whether the blocks are sliding or not. {We're looking for an answer like “if this is bigger than that, they’re sliding”) What is the tension in the string in that case? T yee Po — fe my? Ma he \ why QS ,, | Prig Af. TH mg cere F bs N © -(P Oo “7 frag sen 1H wnt N= ng d ng -~-T2 mG y T m2 ang Mesne + 8) 1. nm, ry, (lg Sine « e078) “Hoag wht side - Thaw To mpgurd = [Agi = My & MWe wae T = Mia - “ _ MT an Te mis peed gg ag H6O = MG tnoy l jm magh Coot Mas v. y . Cmte Zz “ % YA FROM FAX NO. + Mar. @? 2083 Ge:25PM Pe 4) (20 points) Train into buffer A 50 ton (50x10? kg) locomotive is pulling ke © into a statian when the engineer realizes he is lo font going too fast (v=10 m/sec). He locks the ke a —| brakes, so the train starts to slide, when it's a Mw distance d=80m from the end of the track. 3 The coefficient of friction is 0.1 while the 7 eet train is sliding. At the end of the track is a spring, which is strong enough bring a train to a stop. It has a spring constant k = 3x10". Please do each part of this problem symbolically, only plugging in numbers at the end. a) With the numbers as given above, does the train hit the spring at the end of the track? b) If the train were to hit the spring while moving at m/sec, how far would the spring compress? Ral tae Locomabve wan YN", Vv, Aistewa “dA” , fo we tfpstd s pdm tem * ong > Remaining Cvrnat to compres a M’ ha apeng 4x Bexw ex joo — OP x 50x10 1% go ~ oe — [700-000 _ Ap eo/0 or ~ an abuse a te a shop before Athieg = Dyes 008 owl hence *F Pople AL brain com ce 7 fia Apurg ’ be ® mire phen ‘ ; wot exe. 2 2 a. [eee (meee. g 7 brn s K axy cM FROM : FAx NOL: Mar. @? S443 82:85PM Pr 5) (20 points) Falling spheres Two spherical balls are dropped from a very large height. One has a radius of 3cm, and the other has a radius of 12cm. The mass of both balls is 0.5kg. a) After they reach terminal velocity, one is moving much faster than the other. Why? b) Which ball will have greatcr kinctic energy when it hits the ground? The larger one, or the smaller one? Why? c) Find the ratio of their kinetic energies when they hit the ground. an . - . ub . ee ball how quate CAT req bh movi Alone han fe dally ball . (hres see q emporme) (2) The treatin ome got wv mw Oe og “f fot due fo A\= nG)en a m = 2.54. (e) mq > €b er hM | Mm Ds Ay = Tia)em mg= Oo eZ pA om, 7 oe mt Gegyhy MZ im v2 7 me 4 / Aa Cpe drag Co-offtud 2 ‘z ote A; projected aved wn 27a, \ tl af spheres. = re. Gr : I YA, vet Terminal . t ies = Ti) 212 ictja{ veloc = ly = L221 tone ° T ay X 2) oe Ll