Homework Statement
a 1450 kg car is towing a trailer of mass 454 kg. The force of air resistance is 7471N[backward]. If the acceleration of both vehicles is 0.225m/s^2[forward], what is the force of static friction on the wheels from the ground?
Homework Equations
I am able to find Force...
Homework Statement
A car is going down an incline with a constant acceleration.
[b]How much work was done on the car by the force of the road going down the hill? (neglect energy losses due to air resistance, rolling friction, etc.)
The Attempt at a Solution
There are 2 forces acting on...
Hypothetically, if I had a sphere and a block (of the same mass and material (hence the same coefficients of static friction for both interfaces) both stationary on a surface, they would require the same force to initiate motion?
Once moving, a coefficient of sliding friction is employed in...
For hollow sphere rolling up incline:
I know that the kinetic friction will equal 2/3 acceleration since:
μgcosθ=2/3a
acceleration = 3/5gsinθ
so...kinetic friction = 2/5gsinθ
But how I do calculate the force of static friction??
This isn't part of a homework question or anything, i was just curious
If an object is at rest, static friction is at work, so for an object to move, on a flat surface, force applied must be greater than the static friction force yes?
But this is not true for kinetic friction, where an...
Hello All,
on paper machine which I work we have such configurations as is showed on the sketch:
http://imageshack.us/photo/my-images/706/systemt.jpg/
a forming fabric (wire) is driven by two rolls, couch roll (with two suctions chamber) and so called FDR (forward drive roll). On the...
Homework Statement
A 45-kg crate is placed on an inclined ramp. When the angle the ramp makes with the horizontal is increased to 24 degrees , the crate begins to slide downward. What is the coefficient of static friction between the crate and the ramp?
Homework Equations
\SigmaF=ma...
Homework Statement
A car can decelerate at -4.90 m/s^2 without skidding when coming to rest on a level road.
What would its deceleration be if the road were inclined at 11° uphill? Assume the same static friction coefficient.
Homework Equations
Force of Static Friction / Normal Force...
There's a box sitting on a plank. The coefficient of static friction is 0.33. I want to figure out at which angle the box will begin to slide if the plank is tilted.
I know the factors that come into play are FN, Fg or Fgx, and Fs.
So far I have
Fnet= FN-Fs-Fg
=FN- μs-sin∅...
There's a box sitting on a plank. The coefficient of static friction is 0.33. I want to figure out at which angle the box will begin to slide if the plank is tilted. I know the factors that come into play are FN, Fg or Fgx, and Fs.
So far I have
Fnet= FN-Fs-Fg
=FN- μs-sin∅
=cos-0.33-sin∅...
If a curve with a radius of 89.0m is perfectly banked for a car traveling 71.0km/hr, what is the minimum coefficient of static friction for a car not to skid when traveling at 91.8km/hr?
I figured out theta = 24. 03degs from the equations F(normal)*cos(theta) = mg and F(normal)*sin(theta) =...
Homework Statement
A coffee cup on the dashboard of a car slides forward on the dash when the driver decelerates from 48 km/hr to rest in 3.7 s or less, but not if he decelerates in a longer time.
What is the coefficient of static friction between the cup and the dash?
Homework...
I've worked through this problem for a while now and can't quite come up with an answer. The problem is as follows:
A block with mass 5 kg sits on an inclined plane of 30°. The coefficient of static friction is 0.1 between the plane and block. A force F is applied in the horizontal direction...
*** Title says static - need kinetic friction!Homework Statement
Find the amount of kinetic friction. A block with mass of 0.422kg slides down a ramp from rest. Given: acceleration = 1.58m/s^2, mass = 0.422kg, theta = 29.0°, velocity two (end): 1.7m/s, and total time is 1.10s. I also need to...
I know static friction can cause an object to accelerate, but also decelerate.
And i also know that static friction never cause energy loss, but I wonder when it causes an object to decelerate, its kinetic energy should decrease, so where is the mechanical energy gone? Has static friction done...
Homework Statement
Which of the following statements are true about Fs, max in the equation mu=Fs, max/Fnormal?
I. Fs, max is exerted perpendicular to the surfaces in contact.
II. Fs, max represents the maximum value of the force of static friction.
III. On a level surface, the magnitude of...
Homework Statement
A uniform rod AB has a length l and a weight W0. End A is in contact with a rough wall, but it is not fixed. A massless cord connects end B and is fixed to the wall at point C. The rod AB is now horizontal and the angle formed between the cord and rod is θ as shown in the...
1. A wooden block of mass 29.0 kg sits on a horizontal table. A wire of negligible mass is attached to the right side of the block and goes over a pulley (also of negligible mass and frictionless), where it is allowed to dangle vertically. When a mass of 15.5 kg is attached to the dangling wire...
Homework Statement
Find coefficient of static friction if shell starts to slip at θ = 60°
known - θ
unknowns - P, r, Normal force, weight
Homework Equations
friction = μ * normal force
The Attempt at a Solution
I do not know where to start. It looks like the picture wants you to...
Homework Statement
http://www.solutioninn.com/images/E-C-S%20%28808%29.PNG
ignore the given FBD below the pic.
Problem said that: there are 3 blocks like in the picture, with weight A = 600lb, B =150 lb, and C = 500. Find force P such that it will move block C. (everything is static...
Homework Statement
See attachment.
Homework Equations
F = μN
The Attempt at a Solution
I attached the FBD I drew. I then did
ƩFx = FA + FBcosθ - NBsinθ = 0
ƩFy = NA -W + NBcosθ + FBsinθ = 0
ƩMA = 19.5NB - 3.75W = 0
ƩMB = 3.75W - 7.5NA + 18FA = 0
FA = μNA
FB = μNB
θ =...
Homework Statement
"The work done by static friction can be:
a) positive
b) negative
c) zero
d) nonnegative
e) any of the above
Homework Equations
W=F*d
F(friction)= μ *FN
The Attempt at a Solution
I thought the answer must logically be "c) zero" because static friction has no distance...
Homework Statement
A 224-kg crate rests on a surface that is inclined above the horizontal at an angle of 20.1°. A horizontal force (magnitude = 543 N and parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of static friction...
The problem:
A car traveling on a flat (unbanked) circular track accelerates uniformly from rest with a tangential acceleration of 1.60 m/s2. The car makes it one quarter of the way around the circle before it skids off the track. Determine the coefficient of static friction between the car and...
Homework Statement
So I have this lab I have to do about finding the relationship between static friction and normal force. So basically I need to find find how the Static Friction and Normal Force relate by doing a lab experiment.
The materials I have are:
Spring balance / scale
Weights...
Hi,
I am very confused. I have searched everywhere online and have drawn free-body diagrams, but I am still confused as to why static fricition, not kinetic friction, provides the centripetal force in a car moving in a circle.
In addition, assuming that the centripetal force of a car...
Can someone please explain why static friction points in the same direction as the centripetal force for an object (like a box) on the flatbed of the truck that is traveling in uniform circular motion?
Thanks in advance. :)
Homework Statement
A 62 kg crate is dragged across a floor by pulling on a rope attached to the crate and inclined 16° above the horizontal. (a) If the coefficient of static friction is 0.57, what minimum force magnitude is required from the rope to start the crate moving? (b) If μk = 0.31...
Homework Statement
A uniform 7.7 m tall aluminum ladder is leaning against a friction-less vertical wall.
The ladder has a weight of 291 N.
The ladder slips when it makes a 59.0◦ angle with the horizontal floor.
Determine the coefficient of static friction between the ladder and the floor...
I'm a bit confused about the presence of a static friction FORCE.
So here's the question:
The potential for static friction is always present due to the nature of the contact surfaces and the normal force. But is a static friction FORCE always present or does it arise in response to...
Homework Statement
A constant horizontal force F of magnitude 10N is applied to a wheel of mass 10 kg and radius 0.3 m. The wheel rolls smoothly and the acceleration of its center of mass is 0.6 m/s^2. What is that frictional force on the wheel?The Attempt at a Solution
ok so the frictional...
Homework Statement
In Formula 1 race, the cars approach curves
from the outside, cut through to the inside, and
then drift again to the outside (red path AA’ in the
figure). However, the blue path (BB’) in the figure
is shorter. Then why do not the drivers follow the
shortest path? Give...
Homework Statement
A car rounds a banked curve. The radius of curvature of the road is R, the banking angle is θ, and the coefficient of static friction is μ.
a) Determine the range of speeds the car can have without slipping up or down the road.Homework Equations
Newton's second law, as...
I remember doing an experiment in Physics class to find the coefficient of friction with gravity.
We set an object with a flat surface on top of a ramp, and adjusted the ramp angle so that the object would move down the ramp at a constant velocity. Then we measured the angle of that ramp to find...
Below are six crates at rest on level surfaces. The crates have different masses and the frictional coefficients [the first value is the static friction and the second is the kinetic friction] between the crates and the surfaces differ. The same external force is applied to each crate, but none...
Homework Statement
To move a large crate across a rough floor, you push on it with a force F at an angle of 21° below the horizontal, as shown in the figure. Find the force necessary to start the crate moving, given that the mass of the crate is m = 37 kg and the coefficient of static friction...
When a car is moving on a circular track which is sloped away from the centre of the track, is the static friction keep that car on the circle (constant speed) towards the outside of the circle, opposite the acceleration?
I'm having trouble seeing this because to me, the car would want to...
Homework Statement
A 12g coin slides upward on a surface that is inclined at an angle of 14degrees above the horizontal. The coefficient of kinetic friction between the coin and the surface is 0.25; the coefficient of static friction is 0.40. Find the magnitude of the force of friction when...
The other day, we were discussing cars going through turns and the max speed they could do without slipping. My teacher asked us if static or kinetic friction should be used. I answered static, because the wheels are rotating and thus not sliding over the road surface. He ended up saying the...
Homework Statement
A backpack full of books weighing 54.3N rests on a table in a physics laboratory classroom. A spring with a force constant of 200N/m is attached to the backpack and pulled horizontally, as indicated in the figure. If the spring is pulled until it stretches 1.50cm and the...
A 5.00-kg block is placed on top of a 12.0-kg block that rests on a frictionless table. The coefficient of static friction between the two blocks is 0.600. What is the maximum horizontal force that can be applied before the 5.00-kg block begins to slip relative to the 12.0-kg block, if the force...
Block 1 as shown in the link below(url) has a mass of 10.3 kg. The coefficient of static friction between the block and the table is μs = 0.36 and the coefficient of kinetic friction is μk = 0.336.
a) What should the mass of the second block be so that m1 is just on the verge of sliding?
I...
A cart (with wheels) sits on a horizontal table. The front of the cart is a vertical wall, with mass M = 0.313 kg held against the wall. You want to push the cart forward with an acceleration of magnitude a so the mass M can be released and it will not slide down the wall. Assume the coefficient...
Homework Statement
The coefficent of static friction between the floor of a truck and a box resting on it is 0.36. The truck is traveling at 70.0 km/hr. What is the least distance in which the truck can stop and ensure that the box does not slide?
Professor gave us these clues:
It is...
Homework Statement
"If the coefficient of static friction between the block of mass m and the turntable is \mu_s, determine the maximum constant angular velocity of the platform without causing the block to slip." I'm actually using this problem to understand why I'm getting the wrong answer...
Homework Statement
A bus passenger has her laptop sitting on the flat seat beside her as the bus, traveling at 10.0 m/s, goes around a turn with a radius of 25.0 m. What minimum coefficient of static friction is necessary to keep the laptop from sliding?
Given:
V = 10 m/s
r = 25.0 m...
Homework Statement
from giancoli 5th ed (algebra based)
chapter 4, question 42
Drag race tires in contact with an asphalt surface probably have one of the higher coefficients of static friction in the everyday world. Assuming a constant acceleration and no slipping of tires estimate...
Homework Statement
m = 10kg
static friction coefficient (Us) = 0.4
angle = ?
Homework Equations
If the coefficient of static friction is 0.4, calculate the angle at which the box begins to slide down the plank as it tilts.
The Attempt at a Solution
m = 10kg
Us = 0.4
angle...