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Vertical Circular Motion. 5.7. Loop-the-Loop. As the car or motorcycle goes around loop The centripetal force can be found in four places easily. Loop-the-Loop. F N1 -mg=mv 2 /r F N2 = mv 2 /r F N3 +mg=mv 2 /r F N4 = mv 2 /r. Loop-the-Loop (top). Must have minimum speed at top of loop
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Loop-the-Loop • As the car or motorcycle goes around loop • The centripetal force can be found in four places easily
Loop-the-Loop • FN1-mg=mv2/r • FN2 = mv2/r • FN3+mg=mv2/r • FN4 = mv2/r
Loop-the-Loop (top) • Must have minimum speed at top of loop • FN3+mg=mv2/r • FN3 = 0 if barely touching • mg=mv2/r g = v2/r
Loop-the-Loop (top) • If FN = 0 at top of Loop • No force from the track • Centripetal force provided by weight • Rider experiences apparent weightlessness
Example • A 10-gram Hot Wheels car goes around a vertical loop with radius 5 cm. What speed must it have at the top of the track to maintain contact? • v = 0.70 m/s • What Force does it undergo at the bottom of the loop if it has a speed of 5 m/s? • F = 4.9 N
Practice Problem • Don’t let these problems throw you for a loop! • 142#CQ14 - 16, P36 – 40 • Total of 8 problems