Seite - 37 - in Programming for Computations – Python - A Gentle Introduction to Numerical Simulations with Python 3.6, Band Second Edition

1.9 Exercises 37 1.9 Exercises Exercise1.1:ErrorMessages Saveacopyof theprogramball.pyandconfirmthat thecopyrunsas theoriginal. Youarenowsupposedto introduceerrors in thecode,onebyone.Foreacherror in- troduced,save andrun theprogram,andcommenthowwell Python’s responsecor- respondstotheactualerror.Whenyouarefinishedwithoneerror,re-settheprogram tocorrectbehavior (andcheck that it works!)beforemovingon to thenexterror. a) Insert thewordhelloon theempty lineabove theassignment tov0. b) Remove the# sign in frontof thecomment initial velocity. c) Remove the= sign in theassignment tov0. d) Change the reservedwordprint intopint. e) Change the calculationofy toy = v0*t. f) Change the lineprint(y) toprint(x). Filename:testing_ball.py. Exercise1.2:VolumeofaCube Write a programthat computes the volumeV of a cube with sides of lengthL= 4 cm and prints the result to the screen. BothV andL should be defined as separate variables in the program. Run the program and confirm that the correct result is printed. Hint Seeball.py in the text. Filename:cube_volume.py. Exercise1.3:Areaand CircumferenceofaCircle Write a programthat computesboth the circumferenceC and the areaAofa circle withradiusr=2cm.Let theresultsbeprintedto thescreenonasingle linewithan appropriatetext.ThevariablesC,Aandr shouldallbedefinedasseparatevariables in theprogram.Run theprogramandconfirmthat thecorrect resultsareprinted. Filename:circumference_and_area.py. Exercise1.4:VolumesofThreeCubes We are interested in the volumeV of a cube with lengthL:V =L3, computed for threedifferentvaluesofL. a) Inaprogram,use thelinspacefunctiontocomputeandprint threevaluesofL, equallyspacedon the interval [1,3]. b) Carry out, by hand, the computation V = L3 when L is an array with three elements.That is, computeV foreachvalueofL. c) Modifytheprogramina), so that itprintsout theresultVofV = L**3whenL is an array with three elements as computed bylinspace.Compare the resulting volumeswithyourhandcalculations. d) Makea plotofVversusL.