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.
For this translating block problem, below is the solution. I was wondering why if I took the moment about the center of gravity G, the answer for F would no longer be the same because ##I_G \alpha = -\mu_k N (h/2) + N (b/2) - F*d = 0## because ##\alpha = 0##
$$F = \frac{-\mu_k mg (h/2) +...
If frictional force in system (say a block being pushed on a horizontal surface) is less than or equal to us*N then there is no slipping. Why is it that if the frictional force (Ff) in the system is greater than us*N then there is slipping (I am finding it hard to wrap my head around this)? us...
Given that there is a cylinder rolling without slipping down an incline, the method I was taught to represent the KE of the cylinder was:
##KE_{total} = KE_{translational} + KE_{rotational}##
##KE_{total} = \frac {1} {2} mv_{cm}^2 + \frac1 2 I \omega^2## Where "cm" is the center of mass, and...
Here is the problem statement along with the figure.
Here, I take the right-ward and anti-clockwise directions to be positive.
After the ball collides with the wall, its angular velocity remains the same and its velocity changes direction while remaining the same in magnitude.
Using the...
For part(a) and (b),
The solution is,
Can someone please explain the solutions to (a) and (b) to me? I don't understand where they got 5.77 cm from.
Many thanks!
The coin slipped in Trial 2 at a lower speed because the tangetial acceleration was higher than it was in Trial 1. The coin slips whenever a force overcome static friction. There is a force of static friction acting tangetially to the circle upon the coin causing it to accelerate. If the...
1)When a wheel is stuck in mud it rolls with slipping ,this means that at the point of contact it has a net velocity
As we can see from the image Kinetic Friction acts in the direction opposite to the resultant velocity ,this effectively reduces the tangential velocity at the surface and tries...
Consider an object, say a ball, rolling at a constant speed without slipping to the right on a horizontal surface. Let's consider the ideal case, so no deformation of ball or surface. For rolling without slipping to occur, there has to be friction (static friction as the point on the ball that...
a) From impulse-momentum theorem I have: ##J=mv## so ##v=\frac{J}{m}## and since the ball doesn't slip ##v=\Omega b## so ##\Omega=\frac{J}{mb}## and ##\dot{\theta}=\frac{v}{a+b}=\frac{\Omega b}{a+b}##.
b) I considered the angular impulse: ##-J(a+b)=I_0 \Omega_0 \Rightarrow...
I'm now learning about rotational motion without slipping and it's really hurting my brain to think about. Imagine a cylinder rotating on a flat plane.
I can accept that there is both translational and rotational motion. For example, a given point on the circumference of the cylinder follows a...
Body A rests on a inclined plane of body B . the angle of slope is α , the coefficient of friction between the two bodies is μ . Body A does not slip on body B because we accelerate body B with a. What is the minimum and maximum acceleration required for body A not to slip? What will be the...
The acceleration and velocity of a body rolling down without slipping on a frictionless inclined plane are given by
$$
a=\dfrac{mg\sin \theta }{m+\dfrac{I}{r^{2}}}=\dfrac{g\sin \theta }{1+\dfrac{K^{2}}{r^{2}}} \cdots(1)
$$
$$...
So I tried the problem and it’s different from the solution. I’m confused on why my attempt didn’t work, is it because the wheel is undergoing general planar motion? I tried to just apply Newton’s 2nd law to find the acceleration of the centre and then use that to find angular acceleration. The...
I'm letting the weight of the hanger be W.
Since there is no slipping, the total frictional force will be = total weight.
When the load of 50W is placed at X, there'll be a normal force at the left end of the pole on top to the left, and another normal force at the right end of the pole at the...
Summary:: A bowling ball is thrown on a bowling lane with the coefficient of friction ##\mu## with an initial velocity of ##v_0## and no rotation. After hitting the ground, it starts rolling with slipping. After how much time after hitting the lane will the ball stop slipping? What will be its...
Summary:: combining angular and linear momentum when an impulse is aplied 2/3 of the radius from the center.
A Jo-jo is lying on the ground on its edge. The central part (axel) has a radius of 2r and it’s side a radius of 3r. The string is protruding from the bottom of the axel (central part)...
A 6 m ladder weighs 350N and is placed with its lower end on a horizontal floor and its upper end against the wall. The angle between the wall and the ladder is 30°. A man weighing 900N is to climb to the very top of the ladder. The coefficient of friction between the floor and the ladder to...
I don't know how to start it
Is the truck who make the cylinder roll, initially? If yes, how? Since the truck force would pass by the center of the cylinder.
Help me find the friction force when slipping/falling
I already posted this question, but I needed to reword it and include more info.
A 158 lb man runs on a horizontal wet surface at 3 mph before decelerating to 1.5 mph about 4 feet before a right turn. There are cement stairs at the turn...
Basically, I want to know if my assumptions and workings are correct.
This is how I see this situation.
First, I'm viewing this body as a series of disconnected points, like I have in this animation I made, modeling purely rolling motion. Modeling the body like that worked in that case, and...
First we let the static friction coefficient of a solid cylinder (rigid) be ##\mu_s## (large) and the cylinder roll down the incline (rigid) without slipping as shown below, where f is the friction force:
In this case, ##mg\sin(\theta)## is less than ##F_{max}##, where ##F_{CM,max}## is the...
Let ##\Theta## be the angle, following the movement of the center of the disk.
In order to find the kinetic energy, we brake the movement of the disk into 2: The translation of the center of mass, and the rotation of the disk around it.
So, the kinetic energy will be given by:
$$T= \frac 1 2...
Therefore, if someone were to ask what the magnitude of centripetal acceleration is at the top of the wheel at a given instant (relative to the ground):
##v_{cm} = v_{translational, center-of-mass/wheel}##
##ω = ω_{point-of-contact}##
##v_{top} = 2(v_{cm}) = 2(rω)##
##a_{c(top)} =...
Hi
If a rigid disc rolls down an incline plane without slipping then the component of weight down the plane causes the disc to accelerate downwards but the frictional force causes a torque which causes the disc to rotate, At the point of rolling without slipping the velocity of the centre of...
I'm planning on lifting a submersed well pump that is hanging on a 80' 2" galvanized pipe. Total weight is estimated to be 447lbs based on:
pump ~ 50lbs
pipe 3.6lbs per foot
water 1.36lbs per foot
The plan is to use two pieces of wood (1 foot of 2x6) with two clamps to hold the pipe in place...
Firstly, I need to determine what the electric field is causing.
Using left hand rule, the force due to the field is acting down the slope.
Hence my FBD looks like:
Where the two arrows pointing towards the right represent the force due to the field and weight of the cylinder.
Since ...
Ok so please bear with me here and what is almost certainly a really stupid question, partly because I don't quite know how to ask it.
When you have a wheel such as one attached to a car, a torque is applied to it from the engine. It's my understanding that the wheel would slide over the road...
A long horizontal rod has a bead which can slide along its length and is initially placed at a distance ## L ## from one end A of the rod.The rod starts from rest in angular motion about A with a constant angular acceleration ##\alpha## .If the coefficient of friction between the rod and the...
It seems to me that this transition implies going from kinetic friction to static friction. The kinetic friction would apply a torque that would slow down the object's angular velocity, but I'm not sure how this connects to the object suddenly transitioning into rotating without slipping.
Suppose that we have a some rotating object (lets say a wheel with radius R). Let's observe this problem from some reference frame in which center of mass translates with some velocity v and rotates with angular velocity ω. I know that condition for rolling without slipping is v=ωR (point at...
Homework Statement
A thin spherical shell is sliding with velocity ##v_0## on a table initial until friction eventually causes it to roll without slipping. Find its translational velocity when the it rolls without slipping as a fraction of ##v_0##.
Homework Equations
$$I=\frac{2}{3}MR^2$$...
Homework Statement
A bowling ball sits on the smooth floor of a subway car. If the car has a horizontal acceleration a, what is the acceleration of the ball? Assume that the ball rolls without slipping.
Homework Equations
torque = R x F = Iα
aball= Rα
Isphere = (2/5) MR2
The Attempt at a...
Homework Statement
two cylinders of radii r1, and r2
having moments of inertia I1, and I2, about their
respective axes. Initially, the cylinders rotate about their
axes with angular speeds w1, and w 2 as shown in the
figure. The cylinders are moved closer to touch each other
keeping the axes...
Homework Statement
Homework EquationsThe Attempt at a Solution
The initial shape of chain is like an inverted "L" with end B just touching the floor . Height of table is "h" .
My problem is in identifying the net force on the chain in vertical direction .At any instant of time there are...
Homework Statement
A very thin disk of mass m and radius R rolls without slipping along a horizontal plane. The disk is constrained to remain vertical. Let ψ be the angle between the plane of the disk and the x-axis of a fixed frame and θ be the angle measuring spinning of the disk about its...
Homework Statement
Homework Equations
3. The Attempt at a Solution
These are my two observations for this problem .
1) Center of mass of the ring moves in a circle of radius (R-r) about point O . O is the center of the smaller circle in figure 2 .
2) From the geometry , the angular speed...
Homework Statement
I am solving a question that asks for, what's the minimum coefficient of friction required for a cylinder to roll without slipping? Where the cylinder has a force F acting on its center.
Homework Equations
And
The Attempt at a Solution
From the way I understand it, the...
Homework Statement
A hemispherical bowl of mass m and radius R is placed on a rough horizontal surface. Initially the centre C of the bowl is vertically above the point of contact with the ground(see figure).
Now the bowl is released from rest. Find the normal force acting on the hemisphere...
Homework Statement
Two identical cylinders are released from the top of two identical inclined planes. If one rolls without slipping and the other slips without rolling then which one will reach the bottom first? How will their speeds compare when they reach bottom of incline?
I am not sure if...
The setup is a flat friction surface where the ball rolls without slipping. Next, in one case it goes up a friction incline, and in the other a frictionless incline. Which ball leaves the incline faster? Both are given the same initial push.
At the bottom of the incline both balls have the same...
Homework Statement
A solid spherical ball of mass 0.75 kg and radius 5.0 cm is thrown onto a horizontal surface with coefficient of kinetic friction μ . It’s initial velocity at time t = 0 is horizontal and its initial angular velocity is zero. After rolling with slipping for a time t1 = 0.76...
Can someone please help me out with this tough problem?
1. Homework Statement
A ball rolls on a turntable without slipping describe the balls motion in terms of (x,y) for a function of time. (The turntable spins at a constant rate)
(This all the information that the professor gave us.)The...
Homework Statement
In the setup , block C remains at rest and block A move towards left when system is released . If velocity of A is 'u' towards left at an instant , what is the vertical component of velocity with which B descends .What is the horizontal component of velocity of B at this...
I'm a bit confused. We all know that rolling with slipping is associated with kinetic friction.
But Is that friction due to the traslational motion of the center of mass or just the spinning motion?If friction exists because of the translational motion, then in theory, I can slowly lower a...
If I have two wheels with a contact point connection when the one of the wheels is starting a rotation due to a certain torque which condition do the torque have to fulfill in order to:
1) starting the rotation
2) guarantee a rotation without skid
My toughs for now are:
1) the torque has to...