Physics
October02 22lFa1l20o7 Written HomeworkdueTuesday
In the sketchbelow, a massslides along a track from an initial lwel to a higher l-level by moving through an intermediateminimum. The track is frictionless until the tnassreachesthe higher level. On the upper level a frictiond force stopsthe massin a is d. distance The mass'sinitial speed vo:6.0 nrls;the depthof the local minima is2.5 m; the height difference betwenthe two levels is 1.1 m; and the coefficient ofkinetic friction on the upper level is p : 0.60. (a) tWhatis the value of d? (b) What is the value from the initial level to the higher one? (c) of the mass's maximum speedas it progresses local minima is increasedto 5.0 m, how doesthis afFectthe value for d If the depth of the calculatedfor part (a)?
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Physics Fall2007 221
Written HomeworkdueTuesdayOctober02
2-forcesact on a certainsystem. The total potentialenergyof the Only conservative x x is system plottedasa functionof the coordinate below. Give the possible valuesfor points (a), (b), and(c) on the sketch. (d) the systemfor total energyvaluesindicatedby whenx : 0? What is the forceon the svstem
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221Fa1l2OA7 Physics
October02 WrittenHomeworkdueTuesday
Two children are playing a giame@asicallytarget practice) involves that them 3trying to get a marble, shot from a horizontal springJoadedguq mounted on the table, to land in a small box (see sketchbelow). The box is located 2.20 m from the edgeof the the table. Child A compresses spring 1.10 cm and shoots,but the centerof the marble falls 27 cm short of the center of the box. How far should child B compressthe spring in of order for the marble to hit the ce,nter the box? Assumethat there is no fristion on (NOTE: The height of the table and massof marble have either the spring orthe marble. not accidentallybeen left out of the problem.)
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Physics 221Fall2007
WrittenHomeworkdueTuesday October02
4-A 3.00 kg brick is throum vertically upward at an initial speedof 5.00 m/s from a heigtrt of 20.0 m. Choosej up and place the y-coordinate origin at ground level. (a) What is the total mechanicalenergy,E, of the brick? (b) lvlake a graph of the potential energy of the brick as a function of y. (c) Plot the total mechanicalenergy, E, on the sameFaph. (d) For a general y-coordinate, indicate on the Saph what represents the kinetic and potential energiesof the brick. (e) What y-coordinatesare prohibited for the brick?
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