Slipping is a technique used in boxing that is similar to bobbing. It is considered one of the four basic defensive strategies, along with blocking, holding, and clinching. It is performed by moving the head to either side so that the opponent's punches "slip" by the boxer.
This is the second part of a 2 part problem. The first part is:
A solid disc is rolling down a 30 degree incline from rest.
a. draw the force diagram for the disk.
b. write the equations for both translation and rotational motion
c. Find the linear acceleration of the center of mass.
d...
Homework Statement
A stick of mass M and length L is held vertically on a frictionless surface. A gentle push at the top causes the rod to fall from this position . Find the speed of its center of mass when it makes an angle θ with vertical .
a) Use force method
b) Use energy method...
Consider a ball of radius r and total mass m, with a nonuniform but radially symmetric mass distribution inside it, so that it can have an almost arbitrary moment of inertia I. (a) If this ball is projected across a floor with an initial velocity v, and is at first purely sliding across the...
Hi, I'm trying to find out what effect an increase in moment of inertia of a cylinder would have on slipping when the cylinder rolls down an incline.
Starting with: ma=mgsin(theta)-f, where f is the friction force, which is less than or equal to µmgcos(theta), normal force times µ.
We already...
Hi guys,
I'm wondering if I roll a barrel which rolls without slipping down an inclined plane vs. a barrel which only slips down the plane - who will get down faster and how can I show it mathematically ?
Thanks
Hi,
The below questions are NOT HW questions, but I have a big exam coming and I would wholeheartedly appreciate some/any assistance with the following two issues, namely:
(1) Direction of static friction in case of rolloing without slipping
(2) Direction of α and VCM in case of rolling without...
Homework Statement
A rigid ball of mass m = 6kg and radius R = .23 m is sitting on a table. The mass center and geometric center of the ball coincide, but the radius of gyration about its mass center is k = .19 m. The ball is initially at rest. There is a coefficient of friction μ = .435...
We know that in real world scenarios, for rolling without slipping of bodies like sphere, dis, cylinder etc. there is a rolling resistance present. This rolling resistance comes from the fact that in actual situations bodies aren't perfectly rigid. So there is some compression at the point of...
What do we mean by the statement "Rolling with slipping"? I couldn't imagine this situation as a real life scenario.. I mean to say that if the body (say a solid sphere) is slipping/skidding then how can it rotate? If it will be rotating it won't be slipping/skidding. How can the two happen...
I'm trying to wrap my head around how a rolling and slipping sphere would be behave on an incline (with an angle of θ) that is too steep for pure rolling. I believe I understand the behaviour up to that point but once we reach the position where the amount of friction required to maintain...
Homework Statement
A cylinder of radius r, mass m, and rotational inertia 1/2mr2 slides without rolling along a flat, frictionless surface with speed v0. At time t = 0 the object enters a region with friction (with coefficients μk and μs), as shown above. Initially the cylinder slips...
I've been having trouble with this topic for a while now. I've re-read the section dozens of times now, but I'm still not exactly clear and I was hoping for clarification on a couple of things.
In a system of particles, I can see intuitively how the velocity of a particular particle will be the...
Homework Statement
Mike Harris stands at the very top of the sky dome stadium roof to pitch the opening ball for the Blue Jays game. He slips a bit left of centre and slides down along the frictionless roof surface. For what distance, measured along the curve, will he slide before leaving the...
So first of all, hello! I have a question - how much of a torque a car needs to produce that a wheels would start slipping? Let's say i have a car which weights 3200 kg, and has a wheel radius of 0.4394m. So I've been told that to calculate that, i need to do the following procedures(thats very...
Homework Statement
A curve of radius 60 m is banked for a design speed of 100km/h. If the coefficient of static friction is 0.30, at what range of speeds can a car safely make the turn.
Homework Equations
Fun=ma
Ff=μsFn
Fc=mV2/r
The Attempt at a Solution
So, when it is...
sorry, this is is a general question about a conceptual definition I read in my textbook, i hope that's ok.
"an object that rolls without slipping at a constant velocity over a surface with friction experiences no frictional force"
is this true?
i understand that on a frictionless surface, the...
Homework Statement
Homework Equations
Angular momentum/fixed axis rotation
The Attempt at a Solution
Hi guys. I'm having a bit of trouble visualizing what will happen so if you could first indulge me with the mechanics. Imagine there was no friction to begin with; since the force...
hi pf, the more i think i have understood classical rotational mechanics the more it turns out to be clumsy? i am just not able to understand the slipping and rolling of bodies? somewhere friction comes into play and somewhere dont?
"if a body rolls without slipping such that velocity of COM...
In rolling without slipping, why does the point of contact have zero velocity relative to the ground? If so, how can the point of contact move relatively to the ground? (It has to move relative to the ground, otherwise it cannot roll and must stay in its original position)
Homework Statement
Four objects are placed at rest at the top of an inclined plane and allowed to roll without slipping to the bottom
in the absence of rolling resistance and air resistance.
• Object A is a solid brass ball of diameter d.
• Object B is a solid brass ball of diameter 2d.
•...
A massless string is wrapped around a 10 kg cylinder. the picture will look like the letter b. you pull upward on the string with a force of P = 49N. The bottom of the cylinder s on horizontal table and will roll w/o slipping. using dynamics involving center of mass, find the magnitude and...
Homework Statement
See the attachment Q5Homework Equations
The Attempt at a Solution
Let's begin with part (a) first.
After finishing this homework (see the second attachment), I suddenly noticed 1 thing. The friction will gradually decrease to zero and then change the direction to become same...
Homework Statement
A uniform rod of mass m and length l is pivoted at point O. The rod is initially in vertical position and touching a block of mass M which is at rest on a horizontal surface. The rod is given a slight jerk and it starts rotating about point O. This causes the block to...
Homework Statement
This isn't a specific question, more of a general one:
Suppose there is a cylinder of mass m that is rotating in the positive clockwise direction with initial rotational velocity \omega_0, and radius R.
Then, suppose this rotating cylinder is placed on a surface with...
Homework Statement
The rectangular steel yoke is used to prevent slippage between the two boards under tensile loads P. If the coefficients of static friction between the yoke and the board surfaces and between the boards are all 0.25, determine the maximum value of h for which there is no...
Homework Statement
A 1-mg ant is located near the center of a horizontal record (radius = 7 inches) which is rotating at 78rpm. The coefficient of friction between the ant and the record is 0.7. How far out towards the edge of the record can the ant walk before it will slip?
Homework...
Homework Statement
The cylinder is released from rest on the inclined plane. The coefficient of friction between cylinder and plane is μ. Determine the motion of the cylinder, assuming that μ is large enough to prevent slipping.
Homework Equations
The Attempt at a Solution
ok don't...
I never really thought about it but it seems arbitrary in which way we calculate friction in terms of problems involving rolling without slipping. That is you will get the same results whether you say the friction helps your rotational acceleration or your translational acceleration.
For...
We are given with an hollow thin cylinder that has a mass of M and radius R, and a full cylinder that has a mass of m and radius r. The full cylinder is glued to the bottom of the hollow cylinder
(As in the picture - ignore the speed v0 that is drawn in the picture) and now the hollow cylinder...
First I want to introduce a exercise I tried to solve, and then the doubt I have at the final resolution.
"In a slope with θ angle to the horizontal plane, a homogen ball with radius R and mass m roll down without slipping. Calculate the friction force."
Force equilibrium ma = mg sinθ - Ff...
So I have a bad knee. The ACL was stretched and slightly torn several years ago and I needed to get surgery. Since then it has happened occasionally that my knee feels as though it "slips" slightly out and back into the joint. I suppose this may also be the ligament "slipping". Either way...
Hi. I'm taking a look at this problem:
And my doubt is with step 2 when he calculates the torque. He just says it is Fd. But...why? F only has a component which effectivly does torque.
Thanks
Homework Statement
I think I have too many equations for unknowns for rolling without slipping. Suppose a wheel is pushed and left rolling along the ground without slipping.
Homework Equations
T = I*alpha, where alpha is the rotation about the wheel's centroid and I is the moment of...
correct me if I'm wrong please:
Initial slip system is [011] (-1-11)
If I have a tensile axis orientated in [-214], as slipping proceeds it will rotate towards the following direction:
[-214] + n[011] = [-225] it will rotate towards the [-225] direction.
once it gets there, there...
Homework Statement
EDIT: A solid homegeneous cylinder of mass M and radius R is moving on a surface with a coefficient of kinetic friction μ(k).
At t=0 the motion of the cylinder is purely translational with a velocity v(0) that is parallel to the surface and perpendicular to the central axis...
Homework Statement
A 2.7kg solid sphere (radius .2m) is released from rest at the top of a ramp and allowed to roll without slipping. The ramp is .5m high and 5.4 long.
When the sphere reaches the bottom of the ramp what is the rotational kinetic energy and the translational kinetic energy...
HI,
I am having some trouble understanding the effects of an impulse on rolling motion, particularly without slipping.
For eg, if we take a sphere of radius R and mass M, then what is the point h above the centre C at which when an impulse is imparted, will cause pure rolling motion...
Hi, I'm trying to solve this, but I keep getting both sides of the equation to be the same >.<
A solid cylinder is initially moving along a flat surface without rotating. Due to the action of friction, it eventually begins rolling without slipping. The coefficient of friction is 0.22, the...
This is my first time posting here, and I was hoping someone can help me with a problem on my homework.
A solid ball is released from rest and slides down a hillside that slopes downward at 65degrees from the horizontal. a) What minimum value must the coefficient of static friction between...
Homework Statement
Two cylinders (radius R) start from rest and roll without slipping down ramps. They both have the same masses and moments of inertia. The ramps are both at the same angle. One cylinder (A) is directly on the ramp. The other (B) is hanging from two smaller cylindrical bits...
Just solved a problem where I found the particular coefficient of friction that a ramp would need for a body with a certain moment of intertia to roll down it.
So let's say i determined this to be 0.5. If now i try to roll my body down a surface with a lower coefficient it wouldn't be able to...
Sorry for not using the proper post format. I'm typing on my phone and the post template doesn't show up.
Question: a box is sitting in the back of a truck which accelerates forward when a traffic light turns green. Which of the following statements is correct if the boxdoes not slip?
The...
Homework Statement
A block weighing 70.6 N rests on a plane inclined at 26.9o to the horizontal. The coefficients of static and kinetic friction are 0.23 and 0.14 respectively. What is the minimum magnitude of the force F, parallel to the plane, that will prevent the block from slipping...
Homework Statement
(Kleppner & Kolenkow - Introduction to Mechanics - 2.17)
The first attached image shows a box on an incline which is accelerated at a rate a meters per second squared. \mu is the coefficient of friction between the box and incline surface. The questions are in the image...
Homework Statement
a uniform rod of length 4.0m of mass M is supported by a cable which is under tension T. The other end rests against as wall, where it is held by friction. The coefficient of static friction is 0.5. An additional mass M is hung from the rod at a distance x from the wall...
Homework Statement
Homework Equations
All the usually relevant circular motion equations involving θ, I, ⍺, τ and ω
The Attempt at a Solution
I've tried to work from the energy of the cylinder (Using Ek = Ktrans + Krot) and equating the energy to its potential energy at the...
I have been struggling with this problem for a couple of hours, I have attempted a few things but have not come up with coherent results... Please help...
Homework Statement
A girl throws a thin hoop to the right with an initial velocity of 4ft/s and with initial angular velocity of...