. A text book of physics, for the use of students of science and engineering . BR2 .(5) Comparison of this with equation (1) (p. 208) indicates that theresults obtained by both methods agree. Expt. 34.—Kinetic energy of a flywheel. In this experiment the wheelis driven by means of a falling weight attached to a cord which is wrappedround the wheel axle and looped to apeg on the axle so that the corddisengages when unwound (Fig. 243). Weigh the scale-pan and let itsmass together with that of the loadplaced in it be M. Let the scale-pantouch the floor and let the cord betaut ; turn the wheel by
. A text book of physics, for the use of students of science and engineering . BR2 .(5) Comparison of this with equation (1) (p. 208) indicates that theresults obtained by both methods agree. Expt. 34.—Kinetic energy of a flywheel. In this experiment the wheelis driven by means of a falling weight attached to a cord which is wrappedround the wheel axle and looped to apeg on the axle so that the corddisengages when unwound (Fig. 243). Weigh the scale-pan and let itsmass together with that of the loadplaced in it be M. Let the scale-pantouch the floor and let the cord betaut ; turn the wheel by hand through«j revolutions (a chalk mark on therim helps), and measure the heightH through which the scale-pan [selevated. Allow the scale-pan todescend, being careful not to assist,the wheel to start ; note the time ofdescent; repeal three or four times and take the average time / seconds. Again allow the scale-pan to descend three or four times, and note the total revolutions of the wheel from start ing to Btopping, being careful not to Fig. flywheel;. XV KINETIC ENERGY OF FLYWHEEL 211 interfere with it in any way; let the average revolutions be »,. Repeat theexperiment, using different values of M and of H. Tabulate the results : Experiment on a Flywheel. No. ofExpt. LoadM. HeightH. Time ofdescentt sees. Revs, while M is descending «1- Total revs. Reduce the results for each experiment as follows : Energy available = potential energy given up by M =I%H (1) Disposal of energy : (a) The energy of M at the instant it reaches the floor is given by Kinetic energy acquired by M =—s— To find the velocity v at the instant M reaches the floor, we haveAverage velocity x t — H ; H Average velocity: t Final velocity =v 2H •(2) M 4H2 ^ Kinetic energy acquired by M =KM =^ • -&- =—j2T Hence the energy which has been given to the wheel up to the instantthat M reaches the floor is, from (1) and (2), .. u 2MH2 .. , „ .(3) (b) Some of this energy
Size: 1290px × 1937px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectphysics
