Friction Definition and 998 Threads

Homework Statement A solid sphere is rolling without slipping on rough ground with an angular velocity w and linear velocity v. It collides elastically with an another identical sphere at rest. Radius of each sphere is R and mass m. What is the linear velocity of the first sphere after it...

A box weighing 87 lb is being pulled with a rope that exerts a force of 60. lb at an angle of 15 degrees with the horizontal. If the coefficient of kinetic friction is .35, what is the kinetic friction?

Homework Statement Provided the following diagram determine the reversed force of P needed to pull out the wedge, A. Homework Equations Given the coefficient of static friction between A and C and between B and D is 0.2 and between A and B static friction is 0.1. Weights of wedges are...

Homework Statement Given the following diagram: When examining the FBD for member AB how does one determine the direction of friction at B? If surfaces B and C exhibit friction. Homework Equations N/A The Attempt at a Solution I know that impending motion for post BC is in the direction of...

Homework Statement In the attachment. Homework Equations Chart of pressure loss due to friction for steel ducts : http://postimg.org/image/4iml9x761/ The Attempt at a Solution I don't understand the deltaP/L column of the results table. Where did the values come from? Shouldn't they all be...

If you were to calculate work done by rolling friction of a wood sphere rolling down an incline and compare it to work done by friction of a wood block sliding down an incline, are the values for the coefficient of rolling and kinetic friction somehow proportional to each other? This is for a...

I have spent quite some time trying to get this, can someone please help me understand this? A plank is being pulled by a constant force F, it rests on top of two identitcal sylinders - there is rolling without slipping. What I don't understand is, why does F(p) - red arrow force, affect the...

As I see it; static friction is what provides the centripetal force, but does it do anything else? When the brother applies tangential force, what will happen with the static friction, because I assume it will start to provide less centripetal force because the tangential speed of the child...

1. Homework Statement A block, of mass M1, on the rough slope shown is attached to another mass M2 by a light, inextensible string which passes over a frictionless pulley as shown in the diagram (the coefficient of friction between the block and the slope is u ). The block is released from...

I was mixing sugar in a glass of lemonade. As i stirred the spoon I thought that if I move the spoon faster it would cause the lemonade to heat up and thus increasing the temperature. Will the spoon cause heat to be generated in the lemonade? Also answer the title question.

1. A box of mass m = 59.0 kg (initially at rest) is pushed a distance d = 83.0 m across a rough warehouse floor by an applied force of FA = 204 N directed at an angle of 30.0° below the horizontal. The coefficient of kinetic friction between the floor and the box is 0.100. Determine the...

Hi, I need to run wind tunnel tests on a simple shape which will be made of foam whilst the skin friction is to be negligible. Is there easy ways of cover the model to achieve this ? thanks

If I am rotating an object into the ground ( drilling machine) how can i convert all the heat into something useful without wearing the drilling machine? without using drilling fluid to cool it down. like should i use certain materials that can resist the heat from friction or can i like use the...

does rubbing your hands together in space make them warm? like if there is no air in a room will friction between your hands generate heat?

I am unsure how the process works, can somebody please help me out!

Homework Statement A 74.5 kg snowboarder heads down a 16.0° hill that has a height of 78.4 m. If the hill is assumed to be frictionless and there is horizontal wind with a force of 93 N acting against the snowboarder, find the speed of the snowboarder as they reach the bottom of the hill using...

Homework Statement The semicylinder of mass m and radius r lies on the rough inclined plane for which ϕ = 10∘ and the coefficient of static friction is μs = 0.3. Determine if the semicylinder slides down the plane, and if not, find the angle of tip θ of its base AB Homework Equations f=uN The...

A clown balances a small, spherical grape at the top of his bald head, which also has the shape of a sphere. After drawing sufficient applause, the grape starts from rest and rolls down without slipping. It will leave contact with the clown's head when the radial line joining it to the curvature...

Homework Statement A car of mass (m) is attached to a cable of length (L) to a rotating pole. The car will speed up and travel in a circle. If the maximum speed of the car is vmax, what should the minimum strength of the cable connecting the car to the pole be? Note the surface is not...

Homework Statement Hey new to forum here... Grade 11 physics student... Love physics and math! But this one question seems easy but I can't seem to get through... Here it is : A 1100kg car accelerates at 3.40 m/s. If the wheels exert a force of 5600N on the road, calculate the force of friction...

Homework Statement A small block sits at the midpoint of a 2.0 m plank lying on a level floor. A student slowly raises one end of the plank until the block starts to slide. At that instant, the raised end is 0.55 m above the floor. Find the coefficient of static friction between block and...

Homework Statement Find acceleration of block on the way down incline. The incline is 40 degrees and made of steel. The block is also made of steel. μs = 0.6 μk = 0.3 mass of block = 2.00 kg Homework Equations a = g (sinθ - μcosθ) a = F/mThe Attempt at a Solution My friend is getting 4.04...

I think I have solved my problem for a friction force between a bolted assembly, or at least I think did. If a torque was given of 267.6 in-lbs and a constant of k=0.2 and the diameter(d) =0.5, T=k*P*d should equal 267.6=0.2*P*0.5, resulting in P=2676lbs. Then using the equation: Tc=F*fc*dc/2...

Homework Statement Apologies in advance if this problem has been brought here before, I searched and couldn't find it. The automobile has a mass of 1.7 Mg and center of mass at G. Both the front and rear brakes are locked. Take μs = 0.3 Determine the towing force F required to move the car...

Homework Statement A child pulls a friend on a sled. The child maintains a constant tension of 29.4 N in the rope. The combined mass of the friend and sled is 30.0 kg, and the coefficient of sliding friction between the sled and snow is 0.1. How far can the child pull her friend in 6 sec...

Homework Statement When an 8.0 N force is exerted horizontally on a 10.0 kg block, the block’s acceleration across a level surface is 0.2 m/s2. a. Find the coefficient of kinetic friction between the block and the surface. b. Find the frictional force on the block. c. Find the net...

Homework Statement Homework Equations Et = Ek + Eg + Ee The Attempt at a Solution Top:[/B] Et=mgh+1/2k1 Δx12 +1/2k2Δx22 196h+400+600 = ET Bottom: Et=1/2k1Δx22+1/2k2Δx22 400+600=1000 ...and that's when I realized I must have done something wrong. Sorry, I'm kind of bad at this stuff...

Homework Statement There is a string that is attached to a bar as shown below in the picture. What is the coefficient friction between the bar and floor before bar starts slipping. Reference...

Homework Statement Question: [/B]A 600-kg car traveling at 30.0 m/s is going around a curve having a radius of 120 m that is banked at an angle of 25.0°. The coefficient of static friction between the car's tires and the road is 0.300. What is the magnitude of the force exerted by friction on...

For conditions where an object is rolling without slipping on a rough, flat surface, the object posses a net torque about the center of mass provided by friction at the contact point. Hence, why doesn't the object accelerate radially indefinitely? For ex, if we had a slippery bowling ball...

Homework Statement A cart roles down the track with an initial velocity vo. Because of falling rain, water starts filling the cart such that its mass increases linearly with time. The rain that has fallen on the track cause the wagon to experience a frictional force characterized with a...

Homework Statement Homework EquationsThe Attempt at a Solution I had someone help me with this problem (not on here) and their process and units don't seem to match to me. Or is this correct?

Homework Statement At the instant shown, the driver of the truck has just pressed the accelerator pedal down and the truck has suddenly acquired a tangential acceleration of 2.2m/s^2. Coefficient of static friction between crate and tray = 0.4 Coefficient of kinetic friction between crate and...

I am having my students do a lab to calculate the coefficient of static friction along a ramp. They are calculating the coefficient of static friction between felt and the table to be something like 0.40, yet when i did this lab, but along a horizontal surface, and not with a ramp, i get a...

Hello all. I have a doubt about the work done by friction force on a wheels , in two diferent situations: a) In Morin's mechanics book, chapter 5 (page 146) he considers the situation in which a car is braking without skidding. He claims that the friction from the ground on the tires causes...

Homework Statement A block is held between two walls. One static, one applying a force. If the block weighs 5kg, and the coefficient of static friction between each wall and the block is 0.4, what horizontal force is required by the wall applying it? Do both walls contribute an equal vertical...

For my final year project at uni, I am designing a new racquet grip. Past of investigating current products, I am going to test the friction properties of current grips. My plan is to rub a number of grips for a set time and then, using a heat sensor gun, measure the grips heat. My question...

Homework Statement A 3.0 kg block is held against a spring with a force constant of 125 N/m. The spring is compressed by 12 cm. The ice is released across a horizontal plank with a coefficient of friction of 0.1 A) Calculate the velocity of the block just as it leaves the spring. Assume the...

Consider a object of 5 kilos which is fixed with 4 rolling tyres (like in a trolly) which is in a slanting position of 30 degree angle. My question:How to find the force required to move the object upwards the slope along with rolling resistance considered? I tried the force using the F push...

It is possible to convert frictional energy into electrical energy directly?... please tell me and if possible give me the formulae...

This is not a specific problem. It pertains to all the problems I'm working on and only requires that I have one concept explained. If an object is being pulled up a plane by a force parallel to the plane, does the friction work against the parallel component of the gravity or the force pulling...

Homework Statement Find the minimum mass that is needed to get the system moving and the acceleration of the system once it starts to move. The coefficient of static friction between the mass and the table is 0.54 and the kinetic friction coefficient is 0.3. Homework Equations...

Homework Statement This is my problem in all its glory. Homework Equations f = uN The Attempt at a Solution For part a I simply did that tan(alpha) = f/N and therefore alpha = arctan(f/N). This simplifies to alpha = arctan(u). I believe this part is correct. The second part of this question...

Homework Statement At a construction site, a 62.0 kg bucket of concrete hangs from a light (but strong) cable that passes over a light friction-free pulley and is connected to an 80.0 kgbox on a horizontal roof (see the figure (Figure 1) ). The cable pulls horizontally on the box, and a 50.0 kg...

Homework Statement Two blocs with the same mass have the same rope which links them. The friction coefficients are the same whatever the surface. The blocs are initialy stationary and we let them move. What is the module of the acceleration of the blocs if static coefficient of friction =0,25...

I have an Atwood Machine. I have an aluminium Pulley of radius 4 inch. A gym cable running over it. Not sure coefficient of friction but smooth movement. One end of rope, I attach wt. of 0.5 kg. I had to attach weight of 1 kg for acceleration to start. If I attach 2 kg, I had to attach 3.1 kg...

Homework Statement Two blocks are arranged at the ends of a massless string as shown in the figure. The system starts from rest. When the 2.33 kg mass has fallen through 0.315 m, its downward speed is 1.31 m/s. The acceleration of gravity is 9.8 m/s^2. What is the frictional force between...

Can someone please explain me the direction of static friction? I know kinetic friction is always going against the motion of an object but for static friction it depends.