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 In this problem you will consider the motion of a cylinder of radius r_cyl that is rolled from a certain height h so that it "loops the loop," that is, rolls around the track with a loop of radius r_loop without losing contact with the track. Unless otherwise stated, assume that friction is sufficient that the cylinder rolls without slipping. The radius r_cyl of the cylinder is much smaller than the radius r_loop of the loop. b)Find the minimum height h that will allow a solid cylinder of mass m and radius r_cyl to loop the loop of radius r_loop. just need help to get started on this equation. i know it has something to do with finding the critical velocity at the top of the loop, i dont know where to go from there though any help will be fantastic thanks! ...

 When you roll (or slide) something through a loop-de-loop, why do you have to start the track higher than the top of the loop? I'm not talking about something that propels itself, like a toy race car with a motor. Imagine a track with zero friction. You have a track that leads down into a loop-de-loop. The loop reaches a height of 1 meter. The part of the track that leads down has to start HIGHER than 1 meter, even considering zero friction. I remember this fact from physics, but I don't understand why. Can anybody explain this to me? It doesn't matter whether the object slides (like a small block) or rolls, as long as you assume zero friction. ...

 I?m having some difficulty in understanding nested loops so please explain as easy as possible. This is for finding 50 primes. Here?s the code. public class FindPrimes { public static void main(String[] args) { int nPrimes = 50;// The maxium number of primes requried OuterLoop: for (int i = 2; ; i++)// This loop runs forever { //Try dividing all integers from 2 to i-1 for (int j = 2; j < i; j++) { if (i % j == 0)// This is true if j divides exactly continue OuterLoop;// so exit the loop } // We only get here if we have a prime System.out.println(i);// So output the value if (--nPrimes == 0)// Decrement the count break; } } } Tell me I?m right or not. First OuterLoop runs and we have i = 2; in outerloop. Then inner loop executes where j = 2; now we come to if where we check (i%j == 0) in other words (2%2 == 0) so it is true it executes cuntinue OuterLoop; now we have i = 3; here need some explanation down to inner loop perhaps j again initialized to 2. so in if statement this happens (i%j == 0) in other words (3%2 == 0) it is false we have a prime. I want to know this when i becomes i = 10; will it happen in inner loop (7%2 == 0) , (7%3 ==), (7%4 == ), (7%5 == 0), (7%6 == 0) . It will be checked that 7 is prime or not by dividing 7 with all numbers less then 7 in inner loop. Then again OuterLoop. If I?m wrong please explain this ...

 A closed loop carries a current that increases with time. Which one of the quantities listed below relates the emf induced in the loop to the rate at which the current is increasing? a. resistance of the loop b. capacitance of the loop c. self-inductance of the loop d. power dissipated by the loop e. mutual inductance of the loop Thanks :) ...

 a block of mass sliding without friction along a single looped track is to remain on the track at all times, even at the very top of the loop radius. A) in terms of the given quantities, determine the minimum release height. Next if the actual release hight is 2h, calculate (B) the normal force exerted by the track at the bottom of the loop, (C) the normal force exerted by the track at the loop's top and (D) the normal force exerted by the track after the block exits the loop onto the flat section. note: the mass is under the top of the loop. ...

 i really need some help with loop control, i have to do a bit of work by tomorrow or il fail. if you know anything about this subject could you please list me 5 similarities of Open loop control & Closed loop control... and 5 differences of Open loop control & Closed loop control ...

 If I were to place a for loop into another for loop like for(....) { etc... for(....) { etc.... } } which loop would be triggered first? would it be the outer most loop then trigger each inner loop once, or will it do the outer most loop first then cycle through each loop nested inside and then finish off the outer loop? Forgive me if that sounded a bit confusing wasn't sure how else to explain it. ...

 A cart slides down a frictionless inclined track to a circular loop of radius R = 13 m. In order for the cart to negotiate the loop safely, the normal force acting on the cart at the top of the loop, due to the track, must be at least equal to the cart's weight. (Note: This is different from the conditions needed to just negotiate the loop.) a) What must be the minimum speed |vmin| of the cart at the top of the loop? b) How high h above the top of the loop must the cart be released? c) When the car is descending vertically in the loop (point (c) in the picture), what is its speed |v|? d) At the bottom of the loop, on the flat part of the track, the cart must be stopped in a distance of d = 20 m. What retarding acceleration |a| is required? PICTURE FOR PART C ...

 A small solid marble of mass m and radius r will roll without slipping along the loop-the-loop track shown in Fig. 12-34 if it is released from rest somewhere on the straight section of track. For the following answers use m for the mass, r for the radius of the marble, R for the radius of the loop-the-loop and g for the acceleration due to gravity. Figure 12-34 (a) From what minimum height h above the bottom of the track must the marble be released to ensure that it does not leave the track at the top of the loop? (The radius of the loop-the-loop is R. Assume R r.) (b) If the marble is released from height 6R above the bottom of the track, what is the magnitude of the horizontal component of the force acting on it at point Q? ...

 A small spherical ball of radius r = 1.7 cm rolls without slipping down a ramp and around a loop-the-loop of radius R = 3.1 m. The ball has mass M = 345 g. How high above the top of the loop must it be released in order that the ball just makes it around the loop? Repeat problem (a) for a disk. Find the ratio of the heights h for the two cases. I used conservation of energy and set mgh = KE(rot) + KE(trans) + mg2R. Using V=sqrt(Rg), I found the minimum speed the ball must have at the top of the loop and found it to be 5.512 m/s. For the right side of the equation, I used KE(rot) = 1/2Iw(omega)^2. For a spherical ball, I =2/5MR^2. Now I have mgh = 1/2mv^2 +1/2(2/5)MR^2(w^2) + 2mgR M's cancel w = v/R So I was left with h = (1/2(v^2)+1/5(R^2)(v/R)^2 + 2gR) ---------------------------------- g h = 8.37m h-2R = H = 2.17m Is that right? and how would I do it for a disk. ...

 Will you please help me with my report and give me atleast 5 examples of for loop and while loop.. It doesnt have to be very complicated.. Just an example of a simple for and while loop program to report. Thanks.. *i can't figure what program to create so please state atleast 5 for and while loop example. ...

 I need some links to sites about loop pedals that arent review sites or online stores. If anyone knows a lot about loop pedals id love some info. i know its pretty obvious, you record it and then play it back but i have to do a persuasive speech about why a second guitarist is better than a loop pedal. any info or suggestions on arguments would be appreciated ...

 Everytime I try to do a waltz loop and a loop jump I drop my other foot 3/4 through the spin. I've practiced my backspin a ton so I can get the feeling of my foot being crossed but it doesnt work! Any tips on how to keep my foot up? Thanks.=] ...

 PE=KE? is that what I use here? mgh=1/2mv^2? These problems confuse me A windup car does a loop-the-loop. If the initial speed is 4.0m/s, what is the largest value that radius r can have if the car is to remain in contact with the circular track at all times? A wrecking ball wings at the end of a 10m cable on a verticle circular arc. The cran operator manages to give the ball a speed of 6m/s as the ball passes through the lowest point of its swing and then give the ball no further assistance. Friction and air resistance are negligible. What speed vf does the ball ahve when the cable makes an angle of 30 degrees with respect to the vertical? ...

 a loop of wire is shown in a magnetic field of strength 2.5T. The dimensions of the loop are shown in the two view diagram A current of .70A is flowing through the circuit , what is the force on each wire. what is the toatl torque acting on the loop and how will i know when the torgue is zero on the loop what will it look like? the field is in the upward direction and their is a rumbus across the field with a line running around it. Current is moving in the counter clockwise direction. Long sid is 1.0 m and short side is .5m With the side view the current is running towards the top right hand corner with B=2.5T and a 60 degree angle between the line and the first field moving up if you are confused please email me i need a lot of help and completly confused! ...