Constant Acceleration Model

Transcription

1 Honors Physics / Uni 03 / CAPM Nme: Consn Accelerion Model Uni I Consn Velociy Model Uni III Consn Accelerion Model 1 from Modeling Workshop Projec 2006

2 Skech nd lbel he seup: Rmp nd Cr Inesigions Honors Physics / Uni 03 / CAPM Wh could we mesure? How could we mesure i? Use his spce for noes, skeches, ec from he discussion. from Modeling Workshop Projec

3 Honors Physics / Uni 03 / CAPM Wlk-A-Grph From Minds-On Physics (1) A mrble is rolled consn speed long horizonl surfce owrd he origin. The mrble is relesed disnce of 1 meer wy from he origin. (2) A block sis res on ble 1 meer boe he floor. Tke he origin o be he leel of he floor. (3) A bll is dropped from heigh of 2 meers boe he floor. Tke he origin o be he poin from which he bll is relesed. (4) A bll is rolled long horizonl surfce. The bll srikes wll nd rebounds owrd he origin. (5) A cr is prked on seep hill. (1) (2) (3) (4) A block is dropped from res wih heigh of 1 meer boe he floor. Tke he origin o be he leel of he floor. A mrble is relesed from he op of n inclined plne. Assume h posiie is mesured down he plne. A bll is hrown srigh up ino he ir. Tke he origin o be he leel of he floor. A bll rolls long horizonl surfce wihou chnging speed. The bll srikes wll nd rebounds owrd he origin pproimely he sme speed s before. (5) A mrble rolls on o piece of fel, eenully sopping. 3 from Modeling Workshop Projec 2006

4 Prcice 1: Grphs of Moion wih Chnging Velociy 1. Consider he elociy-s-ime grphs nd describe he moion of he objecs. Honors Physics / Uni 03 / CAPM 16 Objec A 16 Objec B (m/s) (m/s) (s) (s) Deermine he displcemen beween 4 nd 8 seconds. Show work Deermine he erge ccelerion during he firs 3 seconds. Show work Describe he moion in words. Skech moion mp. Be sure o include boh elociy nd ccelerion ecors. from Modeling Workshop Projec

5 Honors Physics / Uni 03 / CAPM 2. Use he elociy-s-ime grph o nlyze he moion of he objec.. Gie wrien descripion of he moion. b. Skech moion mp. Be sure o include boh elociy nd ccelerion ecors. c. Deermine he displcemen of he objec from = 0 s o = 4 s. d. Deermine he displcemen of he objec from = 4 s o = 8 s. e. Deermine he displcemen of he objec from = 2 s o = 6 s. f. Deermine he objec s ccelerion = 4 s. g. Skech possible posiion-s-ime grph for he moion of he objec. Eplin why your grph is only one of mny possible grphs. 5 from Modeling Workshop Projec 2006

6 Prcice 2: Chnging Velociies Honors Physics / Uni 03 / CAPM 3. The ble shows some posiion nd ime d.. Use he double inerl mehod o clcule he elociy = s. Show your clculion below. Time (s) Posiion (cm) Velociy (cm/s) b. Use he double inerl mehod o clcule he elociy ech ime nd fill in he res of he ble Consider he elociy-s-ime grph.. During which ime inerl(s) is he ccelerion posiie? During which ime inerl(s) is he ccelerion negie? How do you know? b. A wh ime or imes is he ccelerion zero? How do you know? Velociy m s Time s c. Use he ngen slope mehod o clcule he ccelerion ime = 10.0s. d. Describe he moion of he objec in words. In your complee senences, you migh wn o use phrses like speeding up, slowing down, in he posiie direcion, in he negie direcion, reerses direcion, sring from res. from Modeling Workshop Projec

7 Honors Physics / Uni 03 / CAPM 5. The ccelerion-s-ime grph for cr moing long srigh-line rck is shown below.. Clcule he chnge in elociy oer he firs 3.0 s of moion. 3 2 b. Clcule he chnge in elociy oer he enire 8.0 s of moion. Accelerion cm s Time s c. Gien h he cr srs wih n iniil elociy of +2.0 m/s, plo he elociy-s-ime grph for his moion. (Yep, his is bi ricky go for i Brek he - grph ino useful prs.) 8 6 Velociy cm s Time s d. Describe he moion of he objec in words bsed on he elociy grph h you drew. 7 from Modeling Workshop Projec 2006

8 Honors Physics / Uni 03 / CAPM Scks of Kinemics Cures Gien he following posiion s ime grphs, skech he corresponding elociy s ime nd ccelerion s ime grphs. For ech problem (or pr of problem), ell wheher he forces on he objec mus be blnced or unblnced. If hey re unblnced, sy wheher hey re unblnced in he posiie or negie direcion. Blnced Blnced Blnced Blnced Blnced Blnced Blnced Blnced from Modeling Workshop Projec

9 Honors Physics / Uni 03 / CAPM For he following elociy s ime grphs, drw he corresponding posiion s ime nd ccelerion s ime grphs. For ech problem (or pr of problem), ell wheher he forces on he objec mus be blnced or unblnced. If hey re unblnced, sy wheher hey re unblnced in he posiie or negie direcion. Blnced Blnced Blnced Blnced Blnced Blnced Blnced Blnced 9 from Modeling Workshop Projec 2006

10 Prcice 3: CAPM Rnking Tsks The following siuions illusre he posiion of wo differen blls differen imes. The firs bll ( hrough f) rolls wih consn elociy cross horizonl surfce, while he second bll (g hrough l) rolls wih consn ccelerion down n inclined rmp. Boh objecs re posiion zero ime = 0, nd boh re posiion = d ime = 6 s. () = 0s, pos = 0m (b) = 2s (c) = 4s Honors Physics / Uni 03 / CAPM (d) = 6s, pos = d (e) = 8s (f) = 10s (g) = 0, = 0, = 0 (h) = 2s (i) = 4s (j) = 6s, pos = d (k) = 8s (l) = 10s 6. Rnk ech siuion ( hrough l yes, ll 12 ogeher, no wo sepre liss) ccording o he posiion long he surfce of he bll he indiced ime. Wrie your nswer on single line, using he > nd = signs o show he relionships. NOTE: The picures re no drwn o scle, so you cnno rely on hem o show which bll is hed. Eplin he reson for your rnking. Try o mke single, cler semen h pplies o eery cse rher hn enumering he work for ech cse. Rnk ech siuion ( hrough l) ccording o he insnneous elociy of he bll he indiced ime. Wrie your nswer on single line, using he > nd = signs o show he relionships. NOTE: The picures re sill no necessrily drwn o scle. Eplin he reson for your rnking. Try o mke single, cler semen h pplies o eery cse rher hn enumering he work for ech cse. from Modeling Workshop Projec

11 Honors Physics / Uni 03 / CAPM Prcice 4: Apply he Model 7. Red he following hree problems nd consider if he Consn Velociy Pricle Model (CVPM) pplies. I. A Mc Truck srs from res nd reches speed of 8.5 m/s in 20 seconds. II. A dune buggy rels for 20 seconds speed of 8.5 m/s. III. A drier sees deer in he rod hed nd pplies he brkes. The cr slows o sop from 8.5 m/s in 20 seconds.. For ech of he hree boe problems, sy wheher CVPM pplies, wheher BFPM pplies, wheher CAPM pplies, or wheher none of hose models pply, nd eplin your resoning. b. For one problem where CAPM pplies, drw les hree digrms nd/or grphs o illusre he siuion. Choose he digrms nd grphs h you find mos useful. c. Using he consn ccelerion pricle model, sole for ny unknown quniies. Show your work nd use unis. 11 from Modeling Workshop Projec 2006

12 Honors Physics / Uni 03 / CAPM For he following problems, complee soluion will consis of () les hree digrms nd/or grphs o represen he siuion. (Use he ones you find mos useful.) (b) deerminion of he quniies for which i is possible o sole. (c) cler presenion of he procedure used o produce numericl nswer for ech unknown quniy, wih unis. 8. A cr whose iniil speed is 30 m/s slows uniformly o 10 m/s in 5 seconds. 9. A ber spies some honey 10 m wy nd kes off from res, ccelering re of 2.0 m/s 2. from Modeling Workshop Projec