Hi guys,
So here's one thing which I want to design and this thing involves a flywheel rotating at about 1000 rpm. I need to transfer this energy to another shaft which is stationary with a mechanism. The mechanism has to be actuated for only a second, and then disengaged. During engagement...
Homework Statement
The height of the slope shown in the figure is 30 cm, and its base is 40 cm. A solid cylinder of uniform density, which has the same mass as the slope, rolls down along the slope without slipping. What is the least value of the coefficient of friction between the inclined...
1. Here is the problem http://i.imgur.com/DeCXHNE.png
2. F=-cos45-sin45μ+(weight*μ*cos45)/.5-cos45
3. I plugged the numbers in the equation which we got by combining other equations for F, and I got 9.96 and it isn't accepting it. My other friends used this equation with their problems and they...
Hi guys,
this is a question from one of the subject I'm studying, I find some of them are pretty hard...
(tried to answer them but still seem wrong, except Q1)
Here is the question!
Thanks for the help if you have the time to help me with my questions^^
cheers!
Hi All!
I've been doing some research in an attempt to uncover the proportionality between usable traction, which is defined as the the product of coefficient of static friction and the normal force, and the wheel slip. Given the nature of the the equation for usable traction, I expected that...
Homework Statement
We have a homogenous box on a surface with static friction μ=0.5. We apply a force on the top of the box at an angle 30 degrees to the horizontal (see picture) and we want to know for what values of P does the box slip and tip. I have drawn a free-body diagram here of the...
Homework Statement
Massless and inextensible string is wrapped around the periphery of a homogeneous cylinder of radius R = 0.5 m and mass m = 2 kg. The string is pulled straight away from the upper part of the periphery of the cylinder, without relative slipping. The cylinder moves on a...
How do you use the angle of uniform slip to calculate the coefficient of static friction?
Is there an equation for this? I cannot find it in the module on friction provided with the course... thanks!
I found somewhere that tanθ=μk, but that doesn't really help me, as i am looking for μs...
Hello ,
I have a
60kW hoisting motor with 600 rpm ,10 pole ,crane duty slip ring motor
When the motor is started for its hoisting operation through resistance motor starts slow and immediately goes into full rpm having no sign of resistance.
Does anyone know what might be the reason...
I have a steel component ∅37mm (O.D.) and looking for material/guidelines on a loose tolerance for the housing surrounding it. It needs to be able to fall straight through if held up vertically, easily insertable by hand, while still providing enough axial stability. What's a good diameter for...
Bonding force between two slip guages will be inflenced by surface finish,material,wrining effect etc., what is the relationship between all ? Anyone knows how to calculate theoretically?
Hello, I was trying to solve a problem about induction motors but was baffled at one point.
Here's the question.
Nameplate of a 3 phase induction motor has the following information:
Power = 3kw, speed = 1430rpm, f= 50hz, PF = 0.85, V= 380v
Neglect Stator Impedance.
Q1. Calculate Torque : T=...
Sigh. Who writes Obama's speeches? For many years we fought US press and media so that they will stop mentioning "Polish death camps" instead of "death camps located in Poland". Small difference in wording, but huge difference in meaning. To some extent we were successful, many important papers...
Relation b/w slip ratio and drag force...Race car Vehicle Dynamics help...
hii guyz...
this is the first time i am posting on this forum and hope i ll get help...
I was going through Race car vehicle dynamics by milkins and found a relation given on pg 64
which says...
Drag...
Hello,
I'm having looots of trouble trying to find out the operative slip systems of hcp metals. the slip system is {001}<100> and in my notes it says that there are 3 slip systems and I don't see why! I'm guessing there's only one slip plane the (001) or (0001), and three directions. But the...
Hi everyone,
I've taken a course at uni that may be a little bit over my head, and am pushing through an assignment for it at the moment in an attempt to do well. I've hit a bit of a roadblock on one question though, so am hoping that someone kind here can help me out! The question is...
An 6.40kg block rests on a 12.5kg block. The interface between the lower mass and the table is frictionless, but there is friction (static friction μs and kinetic friction μk) between the two blocks. A horizontal force F acts on the upper block and causes both blocks to accelerate. The...
Consider a bearing joint together with a long pipe (with radius a) by using shrink-fitting. The grip between the pipe and the inner ring of the bearing give rise to the surface pressure p at the interface. If a moment M now is applied to the pipe, what will the slip condition between the two...
Homework Statement
m=6kg
r=0.18m
Fapp=33N
I'm struggling to understand how to answer this question and correlate the linear force applied to rotation without being given the coefficient of friction causing the rotational motion.
The question states that a solid sphere of 6kg is...
The radius of each wheel on a bicycle is 0.400 m. The bicycle travels a distance of 3.0 km. Assuming that the wheels do not slip, how many revolutions does each wheel make?
This problem seems so simple but none of the possible answers available seems correct.
My work
r = 0.4 m
x = 3...
Hello!
I wanted to know if it is possible to calculate the rotor slip if I know the output torque and rpm shaft. I also know the equivalent cicuit of the motor: Rs, Rr, Ls, Lm and Lr.
Thank you!
Homework Statement
There are two blocks stacked on top of each other. M2 is on top of M1. M1 = 3 kg. m2 = 4 kg. μs between the two boxes = 0.6. μk between m2 and the floor = 0.2.
Using a rope, we exert a force T on m2, dragging both boxes 5m. What is the maximum force we can exert on m2, if...
Hey guys,
I'm doing my final year project on an Electronic Drive System using 2 Brushless motors as hub-wheels for a rear-wheel drive. Just using steering angle and the accelerator to determine the differences in speeds for the drive wheels around a corner, etc.
Now I also wanted to implement...
I posted this in "Materials & Chemical Engineering", but it seems a little more active here.
I'm confused with trying to find the slip systems of a simple cubic. I understand the slip plane would be along the plane with the highest atomic density (a close packed plane). But I don't quite get...
non slip ball down an incline of theta!
Homework Statement
A uniform solid sphere rolls down an incline without slipping. If the linear acceleration of the center of mass of the sphere is 0.16g, then what is the angle the incline makes with the horizontal?
Homework Equations
F=ma...
Is it necessary for the channel walls to move for the applicability of Navier's slip condition at the boundary. i.e., Is it possible that the channels walls are fixed, but we can apply the Navier's slip condition at both the channel walls.
Homework Statement
Consider the ladder in the figure. Assume there is friction between the verticle wall and the ladder, with the coeffecient of static friction=0.30. Find the angle at which the ladder just begins to slip.
Homework Equations...
In most tyre models we look at the slip ratio between the tyre and the road to help determine the amount of force that the tyre can generate. My question is, why is it the ratio that is so important?
If a vehicle is doing 100m/s and the tyre is at 90m/s then the relative velocity against the...
Ey guys, this is a problem from my Mech Eng Dynamcis of Machine class
I believe i have the solution already since I've spoken to the lecture'r/tutors who run the subject but would like further clarification just incase I've done something completely wrong.
This is the problem
The...
Homework Statement
A series of small packages is moved by a conveyor belt that passes
over a 300mm radius pulley. The belt starts from rest at t=0 and its
speed increases at a constant rate of 150 mm/s2. The
coefficient of friction is μ=0.75. Determine the time the first...
Hello
I am trying to understand if is it reasonable to use "slip walls" or "zero shear stress" to model smooth walls.
I am working with turbulent air flows in ducts.
Please share your comments.
see diagram
a circular disc of radius r has an initial angular velocity \omega and rolls down a quarter circle ramp of radius R. The initial angular velocity will be very high (e.g. 10,000 RPM) causing the disc to slip. The normalised longitudinal force (i.e. longitudinal force / maximum...
Homework Statement
A uniform ladder of mass, m, and length, l, leans at an angle, \theta, against a frictionless wall. If the coefficient of static friction between the ladder and the ground is \mu_{s}, what is the minimum angle at which the ladder will not slip?
Homework Equations...
Hi
Im working on designing a caster wheel and have a mathematical model that I am following. However I am stuck with how to determine the "tire slip coefficient". Its measured in Newtons. At first I thought its a coefficient so normally would be unitless but only a parameter with Newtons...
Hey all,
I am try to model a problem in which one fluid (of known properties) sits on top of another fluid (with different properties) and there is an imposed slip boundary condition at the interface.
I'm wondering if COMSOL has a Slip boundary condition that can be readily used or if...
ive been given a problem in my school work. it involves 2 veins that have been cut by a fault and displaced along the fault plane. the question gives the orientation of the cut veins on either side of the wall and the orientation of the fault. it asks for the following: net slip, plunge and...
Hi Guys, :smile:
In case of an Induction Generator (IG) connected to grid, the rotor runs at super synchronous (above synchronous) speed exhibiting -ve slip. This is possible since the grid frequency is fixed at say, 50Hz. However, in case of a Self Excited Induction Generator (SEIG), it...
Effect of a pair of slip rings in a DC motor
Hi, I have a question here.
Knowingly that the effect of a slip ring in a DC motor is to reverse the direction of the current in a loop whenever the commutator changes contact from 1 brush to another, so as to ensure the loop to be always...
Homework Statement
A wheel with rotational inertia I = 0.5MR^2 about its central axle is set spinning with initial angular speed w and is then lowered onto the ground so that it touches the ground with no horizontal speed. Initially it slips, but then begins to move forward and eventually...
Homework Statement
The block has mass m. A spring (with spring constant k and equilibrium length b) is
attached to the block at the point x. The free end
of the spring is at the point xb. We move the free end of the spring with a constant
velocity u. The static and dynamic coefficients...
Hi All,
Im having some trouble in one of my classes and can't figure out how to do the following:
If a single crystal of an FCC metal yields with an applied load of 1MPa in the [1 -1 2] direction, at what stress would the same metal yield if the load were applied in the [0 1 4] direction...
I slipped on ice and broke my wrist.
Given our collective knowledge of the physics of slipping, isn't it possible that nano techology exists that allows us to add a non-slip substance to the soles of boots and shoes?
Lev
I am trying to figure out what would be the best way (by best way I mean the cheapest, and simplest effective way) to detect slippage of the wheel. The surface is very low friction, somewhere in the range of 0.05 mu.
Here are my ideas:
Sense current, watch for spikes/troughs
monitor wheel...
Homework Statement
Because the book gives me little information about the cross slip. So I can't handle the basic problem below. I appreciate that you can give me some hints or suggestion.
An f.c.c crystal is deforming by motion of disslocations on the (a/2)[101](11-1) (I use minus instead of...
Homework Statement
Figure shows a block of mass m resting on a 20* slope. The block has coefficients of friction uS=0.80 and uK=0.50 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg.
Part A:
What is the minimum...
I am trying to debug a SUPG FEM code for flow problems (based on Brooks Hughes 1982) and have a question about the Lumped Mass Matrix. My understanding of the Lumped Mass Matrix is that for any given element the mass of that element is simply distributed evenly over the number of nodes.
In...
Hello,
Recently,I study about the slip systems of metals which regarding to the material science subject.
For face centered cubic(FCC),it slip system is {111}<110>.Hence the number of slip systems is 12.The{111}is the family for (111), (-111), (1-11), (11-1),(sorry!-1 means a bar line on top...
Homework Statement
I don't know if I am posting in the wrong thread. This is not a question for solving a homework, but a question to help me write some homework students will have to solve.
I teach algorythmics to mechanics students. The program they are developing is about driving a car...
Current against slip relationship of induction machine??
Please could someone explain to me the relationship between the current and the slip value of an induction machine. I have plotted a graph and I am wondering how to interpret this?
Thankyou.