Radius Definition and 1000 Threads

Homework Statement It is found (through and error) that you will "feel" weightless when you travela round at 42 mph over a smoothy rounded hill. What is the radius of the hill? Homework Equations I'm not sure what equation to use with this problem The Attempt at a Solution the...

Homework Statement You have been hired to design a roller coaster and are working on two sections. The roller coaster rolls on the track, but is not attached. If the cars will have a speed of 35 m/s at the bottom of the hill, what is the radius that the circular bottom section of the...

what is the radius of curvature of a parabola y^2=4ax at the end of the focal chord ?

Hey all, I posted this in a thread with similar discussions but thought to make a new one. Skip to the last two sections if you're in a rush :) About me ------------ I did maths in high school and stats in university but I can't work some (probably elementary) sin / cos / tan stuff out...

We did a experiment, and the aim was to find out that relationship between mass and radius with period of time in the circular motion..Although I know the formula for centripetal force, but I am not sure about what the expression should be The lab data : Table 1: 1st experiment ...

First of all, sorry for bad english. Second of all sorry if such thread is already created, but I really need fast help.Homework Statement There's a lamp in the bottom of the lake. If you watch the lamp from the surface(out of the water) and your eyesight is crossed with the lake, you can see...

Homework Statement how to find the radius of curvature for following curve-: x^2y=a(x^2+y^2) at the point (-2a,2a) Homework Equations radius of curvature= {(1+y1)^3/2}/y2 where y1 and y2 are the first and second order...

Hi, So according to the Thomas-Fermi theory, the formula for atomic radius is R=Z^(-1/3)*(hbar ^2)/m*e^2. (in other words Z^(-1/3) times the Bohr radius) While the total energy has a Z^(7/3) dependence. I need to get this from dimensional analysis. I can get the dependence on h, m, and...

Does anyone know how to even start this problem.. :( I seriously have no idea...spent like few hours to find this out on the library and no luck... Please help a poor guy out...I aint smart enough for this...

Homework Statement Find the series' radius and interval of convergence. What what value of x does the series converge absolutely, conditionally? Sum (n=0 to infinity) (nx^n)/((4^n)((n^2) +1))) Homework Equations The Attempt at a Solution Not quite sure where to start with this...

Homework Statement I'm having difficulty obtaining an accurate value possibly due to unit conversions. Homework Equations r_m=mdot/(2*pi*U*N) r_m=mean radius, ft mdot=mass flow rate, lbm/s U= blade velocity, ft/s N= RPM The Attempt at a Solution I know that I have to convert Rpm...

Homework Statement Determine the radius of a highway curve which has a banking angle of 6% over which vehicles will travel at 120km/h Homework Equations I've started with: Fx = -Fcentripetal = (mv2)/r = -Fnsin6 (mv2)/2 = mgsin6 converted my km/h => m/s ... 33.3m/s The...

Homework Statement I'm attempting to find the orbital radius for a binary system based on the parallax of the system and angular seperation: 1. A visual binary system that is 5 pc away is seen edge-on (i.e. we are in the plane of the orbit). The maximum angular separation of the two stars is...

A few days ago I got really excited when I found the equation for a retangles radius (distance from its center to its perimeter given an angle) I have no idea if this is something very simple and stupid but my math teacher said it was impressive, I'm still in high school It's like this...

Homework Statement "The third turn at the Alamo Cart Dirt Speedway is tilted at 30* and has a radius of 240m. Determine the speed of the Cart Car going around the turn, assuming the car has no help from friction." P.S.: This is not a homework or problem worth any credit. Just an extra...

Homework Statement A water tank the shape of an inverted circular cone with a base radius of 2m and height of 4m. if water is being pumped into the tank at a rate of 2m^3/min, find the rate at which the water level is rising when the water is 3m deep. dv/dt = 2m^3/min h = 3m r = h/2...

Homework Statement Calculate the minimum radius ratio for CN = 3. Givens: Minimum radius ratio for CN = 4 is 0.225, so that's also the max for CN = 3. The Attempt at a Solution I know that the radius ratio determines the CN, which is related to the geometry, and that for a CN of 3, the...

Some places say (including this paper) claim the bohr radius of muonic hydrogen is 285http://ethesis.unifr.ch/theses/downloads.php?file=LudhovaL.pdf Many more peer reviewed papers say it is 256 fm, or 255 fm though. (search for '256 fm muonic' in teh googlez). So who is right? And more...

Homework Statement What is the mass of a planet (in kg and in percent of the mass of the sun), if: its period is 3.09 days, the radius of the circular orbit is 6.43E9 m, and the orbital velocity is 151 km/s.Homework Equations I'm unsure what formulas to use, though these seem relevant. F=...

Thanks in advance for anybody who is kind enough to help me. No this isn't for my homework. I am not even enrolled in school. I am doing some calculations for personal research. But I need to know the ground state radius of a muonic hydrogen atom to help prove my theory. I already know the...

Homework Statement a person is doing pushups and its weight is 584 N, center of gravity is at waist and from waist to hands=.410m and from waist to feet=.840m. find the normal force on each hand and each foot Homework Equations The Attempt at a Solution do u have to find the...

OK I have no idea how to work this out. I've googled bending radius but it doesn't really help a great deal. It's the 2nd part of the last question: http://img535.imageshack.us/img535/4774/10579351.jpg There's nothing in my notes about it, but I guess it has something to do with how...

Homework Statement Find the radius of convergence of the following power series: ∑_(n=0)^∞[(2n+1)/2n] x^n) Homework Equations Ratio Test: lim_n->inf (a_n+1 / a_n) The Attempt at a Solution I got a big ugly fraction that involved both n and x

Homework Statement Assume that the density of positive charge in any Thomson atom is the same as for the hydrogen atom. find the radius R of a Thomson atom of atomic number Z in terms of the radius Rh of the hydrogen atom. Homework Equations The Attempt at a Solution I don't...

Homework Statement The radius of convergence of the sum (from n=1 to infinity) of n!x^n /n^n Homework Equations The Attempt at a Solution I ask way too many calculus questions on here.. This is everything I've done, written really badly.. Ratio test: (n+1)!xn+1/(n+1)n+1 times...

Homework Statement Find the radius of convergence for (sum from n=0 to infinity)7^(-n)x^(n). Homework Equations The Attempt at a Solution The problem above it was a similar sum, (7^n)(x^n). That answer was that the radius of convergence was 1/7. To do this one that I posted up...

Homework Statement A 2 kg car travels in a flat circle. At a certain instant the velocity of the car is 24 m/s West and the total acceleration of the car is 9 m/s 2 at 53 degrees North of West. What is its radius? Answer in units of km. Homework Equations F=ma w=(2pi)/T a= w^2...

An object with a mass M is rotating around an axis, with an arm of radius R at a certain speed V. Assuming that the movement is constant, and a 100% efficiency, how many watt of electrical power can this device generate ? For example purpose, we can take M=60 kg, R=5 meters and V=10 meters...

Homework Statement block 1 with mass of 680 g starts from rest at the top of a frictionless track at a height of H = 4.20 M above the ground. Block 1 collides with block 2 (m = 175 g) at ground level. The blocks stick together and barely complete one turn around a frictionless loop. find the...

Hi to all. Please help me to clarify this situation: There is a 4-wheel cart powered by friction drive using the dc motor. The cart will carry heavy stuffs on the top. what radius of wheels will be able to overcome a 1 cm high and 0.7 cm wide and 14 cm long speed bump(it is like a thin...

Hi to all. Please help me to clarify this situation: There is a 4-wheel cart powered by friction drive using the dc motor. The cart will carry heavy stuffs on the top. what radius of wheels will be able to overcome a 1 cm high and 0.7 cm wide and 14 cm long speed bump(like a thin stick)...

The schwarszchild radius of an electron=1.353*10^-57m, and to work out the volume of a particle assuming it is spherical is 4/3*pi*radius^3 so the volume of an electron at its schwarzchild radius is 4/3*pi*1.353*10^-57^3 = 0??! WHAT DOES THIS MEAN :S

Homework Statement find the roc of: \sum_{n=0}^{\infty}\frac{(n!)^3}{(3n)!}z^{3n} Homework Equations limsup ratio test The Attempt at a Solution i think use of limsup is quite difficult as factorial there. but i do not know how to use the ratio test because z is another...

hi, how do you calculate the classical radius of nucleons or quarks? do you include only the electrostatic potential energy or also some nuclear potential energy?. i have read many times that the classical radius of nucleons is lower than the classical radius of the electron, is it right...

Homework Statement Suppose that we see a planet in our Solar System that we measure to have an orbital period (around the Sun) of 18.0 years. We look at it with a telescope and see that it has a moon. From repeated observations, when the planet is near or at opposition, we note that the...

Homework Statement Beam of silver atoms are passing through air at a temp 273K and a pressure of 1 Pa. The beam is attenuated by a factor of 2.72 in a distance of 10^-2 m. Find the mean free path of the silver atoms and estimate the effective collision radius.. Homework Equations...

Homework Statement I'm trying to create a graph showing the relationship between radius and angular velocity for a toriod space station that maintains a constant angular acceleration of Earth's gravity (9.8 m/s^s) on it's rim. Homework Equations ac = r\omega^2 The Attempt at a Solution...

Homework Statement PHYSICS Gravity exercise!? What is the acceleration due to Earth's gravity at a distance from the center of the Earth equal to the What is the acceleration due to Earth's gravity at a distance from the center of the Earth equal to the orbital radius of the Moon? a =...

Homework Statement A curve of radius 151 m is banked at an angle of 11°. An 798-kg car negotiates the curve at 94 km/h without skidding. Neglect the effects of air drag and rolling friction. Find the following. (a) the normal force exerted by the pavement on the tires (b) the frictional...

Homework Statement while lying flat on a beach you see the sun set, and when the sun disappears you start a timer. Then you stand up, changing the position of your eyes(increasing height) by 1.7m. When the sun disappears from your view again you stop the timer which reads 11.1s. Calculate the...

I have a motor http://www.megabuy.com.au/gearbox-wi...utm_medium=cpc and i want to attach a spindle, like a circular thing directly onto the shaft. the circular thing has to have a radius, such that it lifts 0.5kg but does not lift 1kg, i do not know how to find the radius so it lifts...

Homework Statement Find Radius of Convergence of the corresponding power series solution from Recursion Equation alone: n^2a_{n+2} - 3(n+2)a_{n+1} +3a_{n-1} = 0 \qquad(1) Homework Equations R = 1/L where L = \lim_{n\rightarrow\infty}\left|{\frac{a_{k+1}}{a_k}\right|\qquad(2)...

I have a motor http://www.megabuy.com.au/gearbox-with-motor-12v-70rpm-p204324.html?utm_source=getprice&utm_medium=cpc and i want to attach a spindle, like a circular thing directly onto the shaft. the circular thing has to have a radius, such that it lifts 0.5kg but does not lift 1kg...

Homework Statement Determine the radius of Convergence using the ratio test of: \sum_o^{\infty}\frac{n^6}{3^n+n}(x+4)^{8n+1}\qquad(1) Homework Equations R = \frac{1}{\lim_{n\rightarrow\infty}\left|\frac{a_{n+1}}{a_n}\right|}\qquad(2)The Attempt at a Solution Ok. In order to use (2), we...

Homework Statement radius of the planet: During the transits, the planet blocks 1.1% of the star's light star has a mass of1.17 solar mass and radius of 1.15solar radius Homework Equations Rp=(L)^1/2 (Rs) The Attempt at a Solution so I just want to make sure i did this righ, this...

Geometry Problem Involving Circles and Fixed Radius- Please Help! I have a compass with radius X, and my friend has a compass with radius Y. We both draw a circle with our compasses so that our circles intersect at two points. Call these two points C and D. You draw a common tangent to both...

Homework Statement An alpha particle and beta particle, each with kinetic energy 35keV , are sent through a 1.1T magnetic field. The particles move perpendicular to the field. Homework Equations no idea. The Attempt at a Solution theres nothing on curvature radius in my...

Homework Statement A spherical asteroid has a density of 2600 kg/m^3. I throw a ball at the speed on 20 m/s. If the ball is to travel in a circular orbit, what is the largest radius of the asteroid possible to accomplish this? Homework Equations these are the equations I used.. escape...

Radius of proton due to QED?? In one account of the new findings of smaller proton radius, the claim was repeated several times that the radius of a proton was predicted by QED, in conflict with the new measurement. Why QED? I would think, within a proton, QCD is orders of magnitude more...

Homework Statement The string in the Figure is L = 102.0 cm long and the distance d to the fixed peg P is 73.4 cm. When the ball is released from rest in the position shown, it will swing along the dashed arc.How fast will it be going when it reaches the highest point in its swing? Homework...