{EMS Shock} Student Name: Period:

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1 {EMS Shck} Student Name: Perid: 5 th Grade Engineering Pulleys Unit Rubric Lab #0016 Pulley Frame Pulley Frame: Student cnstructed the Pulley Frame t lab specificatins. Pulley Frame was nt apprved 0 pints Pulley Frame was apprved n 4 th attempt 4 pints Pulley Frame was apprved n 3 rd attempt 7 pints Pulley Frame was apprved n 2 nd attempt 9 pints Pulley Frame was apprved n 1 st attempt 10 pints Questins and Respnses: Student must accurately respnd t all questins in the packet. Nne f the respnses reflect the students understanding f the 0 pints Very few respnses reflect the students understanding f the pints Sme respnses reflect the students understanding f the pints Mst respnses reflect the students understanding f the pints All respnses reflect the students understanding f the 10 pints Ttal Pints f 20.. Lab #0017 Crane Crane cnstructin: Student cnstructed the Crane t lab specificatins. Crane was nt apprved 0 pints Crane was apprved n 4 th attempt 4 pints Crane was apprved n 3 rd attempt 7 pints Crane was apprved n 2 nd attempt 9 pints Crane was apprved n 1 st attempt 10 pints Questins and Respnses: Student must accurately respnd t all questins in the packet. Nne f the respnses reflect the students understanding f the 0 pints Very few respnses reflect the students understanding f the pints Sme respnses reflect the students understanding f the pints Mst respnses reflect the students understanding f the pints All respnses reflect the students understanding f the 10 pints Ttal Pints f 20..

2 ME101: Intrductin t Simple Machines BACKGROUND Terms BLOCK AND TACKLE FIXED PULLEY MECHANICAL ADVANTAGE MOVEABLE PULLEY PULLEY Abut Pulleys Hw d yu raise a flag n a tall flagple, withut standing n tp f it? Mst flagples use a pulley! A pulley is a simple machine made with a rpe, belt, r chain wrapped arund a grved wheel r similar device. Pulleys are generally used t raise, lwer, r mve a lad. A pulley changes the directin f the pull, r effrt. When yu pull dwn n a flagple's rpe, the flag will rise. A single pulley makes a jb seem easier by letting yu pull with the frce f gravity instead f lifting against it. Fr example, yu are asked t raise a 50 kilgram weight. If yu tie a rpe t the weight and try t raise it, yu have t pull up smething weighing 50 kilgrams! If yu run the rpe arund a pulley, yu are pulling dwn; it seems slightly easier because yu can use yur wn weight as a cunterweight. A fixed pulley des nt rise r fall with the lad being mved, and des nt create a mechanical advantage. One f the prperties f a simple machine such as the pulley, is that is it can be used t magnify the frce applied t a task. The mechanical advantage f a machine is the number f times a machine multiplies the effrt, and is the rati f the utput frce t the input frce. A mveable pulley rises and falls with the lad that is being mved and creates a mechanical advantage. A cmbinatin f fixed and mveable pulleys in a blck and tackle als creates mechanical advantage, and reduces the amunt f effrt needed t pull up a lad. Blck and tackles allw a heavy bject t be lifted with less frce! In a blck and tackle, the rpe must be pulled a greater distance as it winds thrugh several sets f pulleys. The trade-ff fr less effrt is mre rpe pulled. If yu are pulling dwn n a rpe n a blck and tackle system, the mechanical advantage is equal t the number f rpes supprting the lad. Cunt each end f the rpe as a separate rpe. Fr example, tw rpe ends supprt a mveable pulley which is cnnected t a 100 kilgram weight. The 1 2 mechanical advantage is 2 and in this situatin, an effrt frce f 50 kilgrams will lift a resistance frce f 100 kg. WOW The fllwing is a class demnstratin that allws students t experiment with pulleys. 1. Yu will need a brm handle r ther stut dwel, duct tape, a length f rpe, and a liquid detergent jug filled with water. 2. Ask students t lift the jug straight up using the rpe and brm handle. Have students share their results. 3. Tape the ends f the brm handle dwn between tw desk tps r ther apprpriate surfaces. Tie ne end f the rpe t the brm hand and lp the rpe thrugh the jug handle. Lp the rpe arund the tp f the dwel, back thrugh the jug handle and lp again arund the tp f the dwel again. The jug handle will act as a mvable pulley. 4. Have students lift the jug by the free end f the rpe. Have students cmpare the effrt between lifting the jug, and using the pulley system t lift the jug. 5. Cmpare the amunt f rpe used lifting the jug with ne lp arund the dwel, and the amunt f rpe used with the tw lps. Des ne system use mre rpe than the ther? Blck & Tackle 32

3 ME101: Intrductin t Simple Machines PROJECT 1: Pulley Frame #0016 Make sure yu have: Build #4 axles 8 - #2 beams 1. In this prject, yu will build a frame and experiment with lifting a weight with a single pulley system. Yu will cmpare it t lifting the weight with a multiple pulley r blck and tackle system! 2. Start by building the frame supprts. Put a 2x4 brick tw studs ver n an 8x16 building brick. Add tw #2 beams n each end f the 2x4 brick. Cver the beams with tw 2x4 plates. Add a third #2 beam n the end f the plates that face the center f the building brick. 3. Add a secnd supprt, identical t the first supprt, n the ther side f the 8 x 16 building brick. 4 - #4 beams 2 - #12 beams 2 - #6 beams 2 - #16 beams 2-2x4 bricks 6 - bushings 8 - frictin pegs 5-2x4 plates 4-2x2 plates 4. Insert a frictin peg int each f the #2 beams. 5. Attach a #16 beam perpendicular t the 8x16 building brick by pushing the first and third hles nt the frictin pegs. Make them face utward. 6. Put tw frictin pegs int the backside f each f the #16 beams in the tw tp hles. Attach tw #6 beams nt the frictin pegs. Be sure they face utward. 1-8x16 brick string 1 - Weight 4 - sm pulleys 33

4 ME101: Intrductin t Simple Machines PROJECT 1: Pulley Frame # Further supprt the frame by placing a 2x2 plate n each side f the #16 beams and the #6 beams. 8. Cnnect the tps f bth #6 beams with tw #12 beams, ne n each side. Secure the #12 beams with tw #4 axles and fur small pulleys. Insert the axles int the end beam hles f the #6 beams and #12 beams and fix the axles int place with the pulleys. This is the frame that will let yu experiment with pulleys. 9. Insert a #4 axle int the furth and eighth hles. Add a bushing between the tw #12 beams t the axle as yu are inserting it thrugh the beam hles. These axles and bushings will serve as fixed unmveable pulleys in a blck and tackle. Set the frame aside. 10. Start the mveable pulley part f the blck and tackle. Place a #2 beam n each end f a 2x4 plate. 11. Put a weight brick n the plate, centered between the #2 beams. Center a #4 beam n each f the #2 beams. 12. Cnnect the tw #4 beams and the weight brick with a #4 beam. Center tw bushings n each f tw #4 axles. Insert ne end f the axles int the first and secnd beam hles f the #4 beams. 13. Add a secnd beam cnnecting the #4 beams and the weight brick, and supprting the ends f the #4 axles. 14. Place the mveable pulley cmpnent between the upright psts f the supprt frame. 34

5 ME101: Intrductin t Simple Machines PROJECT 1: Pulley Frame # Run a string frm ne f the axle-bushing cmbinatins n the mveable pulley cmpnent up t ne f the axle-bushing cmpnents n the frame. Run the string back dwn t the secnd axlebushing cmbinatin n the mveable pulley cmpnent and up and ver the secnd axle-bushing cmpnents n the frame. 16. Here is a picture f the finished mdel. Try this Pull the string and make sure it glides smthly. 2. Lift and drp the weight several times. Develp a sense f hw much effrt it takes t pull it up using the blck and tackle. 3. Red the string s that it is cnnected t the weight and then ges ver just ne f the frame's axle-bushings. Try lifting and drpping the weight several times. Which seems easier? One pulley r the blck and tackle? Single Pulley: Blck and Tackle: 4. Repeat the exercise fr each pulley system several times. Is there a difference in the amunt f string r distance yu must pull t lift the weights up t the same height? Which system used a greater length f string? Single Pulley: Blck and Tackle: 5. Cntinue answering questin n page 35A (the next page...). 35

6 6. Lk carefully hw yu have set up yur blck and tackle. Hw many sectins f line supprt the blck and tackle? 2 sectins f line 3 sectins f line 4 sectins f line 5 sectins f line 7. If yu wanted t mve the lad 2 inches, hw many inches f line wuld yu have t reel in? 2 inches 4 inches 6 inches 12 inches 8. Assuming the ttal lad n the blck and tackle is 30 grams, hw many grams f effrt wuld need t be applied t line #4 in rder t lift the lad? 4 grams f effrt 5 grams f effrt 10 grams f effrt 20 grams f effrt 9. Indentify the fllwing parts f the blck and tackle shwn belw. Write the letters in the diagram with the crrespnding spaces Blck Tackle Lad Effrt 35A

7 ME101: Intrductin t Simple Machines PROJECT 2: Crane #0017 Make sure yu have: Build #4 axles 4 - #6 axles 1. In this prject, yu will build a mdel that uses the frm f a blck and tackle t raise and lwer the bm arm f a crane. Yu will build a mdel that integrates pulleys! 2. Place tw 2x4 plates parallel t each ther. Use them t cnnect the ends f tw #16 beams. Place them underneath the #16 beams. Add tw 2x4 plates n tp f the beams, cnnecting the first and secnd and fifth and sixth sets f studs. Insert a cnnectr peg in the eighth hle f ne f the beams. 3. Insert a #6 axle int the first and last beam hles. Fix the axles int place with small pulleys bushings 1-1x4 plate 7 - cnnectr 4 - med 4 - O rings 7 - #4 beams 3 - #8 beams pegs pulleys 2 - #6 beams 4 - #16 beams 2-2x2 bricks 2-1x6 plates 6-2x4 plates 4. Add a medium pulley t each extended axle end. Put a O ring n each pulley. These are the wheels f the crane! 5. Cnnect the tw upper 2x4 plates with tw 1x6 plates. Cver these plates with tw #6 beams. 6. Center tw sets f bushings n tw #4 axles. 8 - sm pulleys 1 - lg pulley 36

8 ME101: Intrductin t Simple Machines PROJECT 2: Crane # Add a #8 beam n tp f ne f the #6 beams. Insert the bushing axle cmbinatins int the first and third beam hles. 8. Fix the tw bushing-#4 axle cmbinatins int place with a secnd #8 beam. 9. Center tw bushings n a #6 axle. 10. Add a #4 beam n tp f ne f the #8 beams. Insert the bushing--#6 axle cmbinatin int the middle hle and fix int place with a small pulley. 11. After fixing the bushing--#6 axle cmbinatin int place. Add a secnd #4 beam, and n the exterir side add a small pulley and then a large pulley. Insert a cnnectr peg int the large pulley t act as a handle. Cnnect the tw #4 beams with a 1x4 plate. 12. Place tw #4 beams n the #16 beams at the frnt f the crane. Set the vehicle aside. 13. T start the bm arm, cnnect tw #16 beams with tw cnnectr pegs. Add tw 2x4 plates abve the #16 beams. On ne end, attach a #4 beam with tw cnnectr pegs, leaving the first beam hles clear. Insert a cnnectr peg in the last beam hle n the ppsite end f the beams. 14. Center tw sets f bushings n tw #4 axles. Place a #4 beam alng ne edge f the 2x4 plates. Insert the bushing-axle cmbinatins int the first and last beam hles f the #4 beam. Fix the free ends f the axles with a secnd #4 beam. 37

9 ME101: Intrductin t Simple Machines PROJECT 2: Crane # Attach the bm arm by sliding the #16 beam--#4 beam between the tw #4 beams, and sliding an axle thrugh all the beam hles. Fix the axle int place with tw small pulleys. 16. Put tw 2x2 bricks abve and belw ne end f a #8 beam. 17. Add the #8 beam-brick cmbinatin t the end f the bm arm. 18. Tie a piece f string t the #6 axle, and lp the string frm the #6 axle arund the upper #4 axle n the bm arm, back dwn t the first #4 axle n the crane chassis, back up t the lwer #4 axle n the bm arm, and back dwn arund the secnd #4 axle n the crane chassis. Remve the cnnectr peg frm the #16 beam, insert the string int the beam hle and return the peg t hld the string in place. Try this Turn the large pulley. Des the bm arm rise? Yes N 2. Reverse the turning directin f the large pulley. Des the bm arm lwer? Yes N 3. As yu are turning the large pulley, watch the string as it run arund the bushings and #4 axles. D the #4 axles turn as the string travels ver them? Yes N 4. Answer the Questin n the next page... E 38

10 5. Lk carefully hw yu have set up yur crane. Hw many sectins f line supprt the bm arm? 2 sectins f line 3 sectins f line 4 sectins f line 5 sectins f line 6. Lk carefully at hw many lines supprt the bm arm f the Crane. If yu wanted t mve the bm arm 2 inches, hw many inches f line wuld yu have t reel in? (Lk Carefully, this can be trickier than it seems) 2 inches 4 inches 8inches 10 inches 7. Assuming the ttal lad n the crane s bm is 20 grams, hw many grams f effrt wuld need t be applied t line #1 in rder t lift the bm arm? 4 grams f effrt 5 grams f effrt 10 grams f effrt 20 grams f effrt 39