Wall Definition and 735 Threads

I searched the forum before posting and couldn't seem to find anything on the acceleration off a wall that wasnt dealing with force as well. Homework Statement A tennis ball with a velocity of +9.6 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball...

Homework Statement Here is a horrible diagram representing the problem: The problem is to find the minimum coefficient of static friction between the ball and the wall so that the ball remains motionless. Homework Equations torque = r*F The Attempt at a Solution I've divided the tension...

A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 44 m/s (about 99 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (44 m/s). As indicated in the diagram...

Homework Statement An 8.00m uniform ladder whose mass is 55 kg is resting against a frictionless wall. Its lower end is 750cm from the wall. If the coefficient of static friction between the floor and the lower end of the ladder is 0.60, calculate the reactions on both side of the ladder...

Hello, as you can likely see I'm new here. I'll be blunt and state off the bat that I am not a physicist or engineer in any manner. Math has never been my strength which is why I spent my university life within the social sciences. I've always had an admiration for those within the natural...

I hear this from people sometimes. Upon hearing about a bad head on collision, I will hear a person promptly add the two speeds together and claim the wreck for the drivers is as bad as slamming into a brick wall with that new speed (S = s1+s2). Is this really a good analogy? I'm not so sure it...

Lets say you take a ladder and put it on a scale and measure it's weight while balancing it vertical. If you then lean the ladder at varying angles against a wall, would the scale's reading remain unchanged? I take it that it would, but for some reason this seems odd to me. Lets say the...

Consider a 10 m/sec wind blowing against a perfectly rigid wall. I want to calculate the pressure the wind produces on the wall. I'm ignoring the details of the actual physics of compression and turbulence. I'm reducing the problem to one cubic meter of (incompressible) air with a mass of 1.2 kg...

Homework Statement This is a fairly straightforward question I'm sure. I have a ball. This ball has a mass of mass M. I throw this ball with a velocity v against a wall (perfectly along the x-axis (in the positive direction)). Now suppose the ball stays in contact with the wall for a time...

Wall excerts work on skater: Please help :( Homework Statement A 69.0-kg short-track ice skater is racing at a speed of 11.0 m/s when he falls and slides into a padded wall that brings him to rest. Assuming that he does not lose any speed during the fall or while sliding across the ice, how...

Homework Statement Hi again ,, My third Question of the day : A 250-kg block is supported by a cable attached to a rod of mass 100 kg that can pivot at the base. a) Calculate the tension in the tie-rope between the rod and the wall if it is holding the system in the position shown in...

Yes, entanglement has gone mainstream (if it wasn't already) with an article in the 5/6/2009 Wall Street Journal on the subject: Science, Spirituality, and Some Mismatched Socks : Researchers Turn Up Evidence of 'Spooky' Quantum Behavior and Put It to Work in Encryption and Philosophy The...

Homework Statement My main problem here is that I do not understand what they are asking. What is the wall shear stress? Do they mean the stress at the "floor" (or whatever you want to call it)? If so, I am assuming I use Newton's Law of Viscosity \tau=\mu\frac{du}{dy} since this is...

Homework Statement The problem consists of a block that starts off on a ledge. It has an initial vertical imperfection ie it is leaning over at the top such that when the top anchors are cut it will fall off of the ledge. I need to determine how far the block falls from the wall and the...

Homework Statement A vet is using an ultrasonic motion detector to detect the heartbeat of an unborn chimp baby and claims that the speed of sound in the soft tissue of a chimp should be 1489 m/s. According to the manual which comes with the motion detector, the emitted frequency of sound...

Homework Statement A plane wall of 152 mm thickness has surface area of 2.32 m2. One side of the wall is kept at 82.2 oC, and the other side at 4.4 oC. The thermal conductivity of the wall material is 0.036 W/m.K at 0 oC, and that at 93.3 oC is 0.055 W/m.K. Calculate the rate of heat...

I'm looking to understand how to estimate the sound isolation capacity of a wall structure. With rising degree of detail will probably come an exponantial increase in complexity. I'm looking to start of, euhm,... gently. :shy: What I've gathered so far: -The impedance of the wall seems to take...

Homework Statement - FBD of description of forces - Mass of the rider ( is to decide ) = 70 kg - Dimensions of the Ride ( is to decide ) Height = 10 meters Radius = 10 meters Givens: gmax= 4 g Speed of bike = 80 Km/h Mass of Bike = 180 kg mu= vertical coefficient of friction = 1.00...

I have a Samsung 42" similar to this one: http://www.hotchickshotpicks.com/wp-content/uploads/2007/09/samsung-42-inch-tv.jpg except that of course mine doesn't show sports. I've mounted it on a wall support but the TV does not seem stable. I can grab it and wobble it. The wall support is...

Homework Statement 1) A 0.1 kg ball is rolling across the floor at 0.5 m/s when it hits a wall and reverses direction without any change in speed. A) Can you determine the impulse delivered to the ball by the wall? If so, what is it? If not, explain why not. B) Can you determine the...

Hope the subject caught your attention, I just wanted to clarify my some things about ac current... Ok, for our "circuit" we're going to have copper wire for simplicity's sake. Also, we're going to say that our Electric force travels at c on the wire. Just a big loop, no sharp turns, nothing...

Hello! This is my first post, I am taking an introductory physics course during my second semester of college and having some trouble with this problem. I hope I have followed the correct format, I appreciate any help that can be offered! Homework Statement A 4.82 kg block is placed on...

How many decibels does a regular apartment wall cancel out?

Homework Statement In a church choir loft, two parallel walls are 4.98 m apart. The singers stand against the north wall. The organist faces the south wall, sitting 0.967 m away from it. So that she can see the choir, a flat mirror 0.855 m wide is mounted in the south wall, straight in front...

1. A rectangular piece of cardboard 21.7cm high is held 1.0m in front of a point source of light. The cardboard is 2.6m away from a wall. How tall is the shadow on the wall? I have no idea how to do this my prof never talked about this in class and I looked threw the book with no help. I...

When a magnet is dropped from rest near an iron wall, it accelerates downward due to gravity at constant acceleration. It also accelerates toward the wall, and the closer it gets to the wall, the greater the acceleration. Can anyone refer me to a solution that would give the position of the...

Homework Statement A constant volume gas thermometer of volume V contains n amount of moles of gas. Assume the gas obeys the ideal gas law pv=nRt. The behavior is better described by: \left(p+a\frac{n^2}{V^2}\right)\left(\frac{V}{n}-b\right)=RT a=0.1, b=3e^-5. The thermometer is calibrated...

[solved]Average force exerted on object by wall Handball A 301.0 g handball moving at a speed of 5.3 m/s strikes a wall at an angle of 29.0° to the normal of the wall and then bounces of with the same speed at the same angle. It is in contact with the wall for 0.002 s. What is the average...

Does anyone believe, given new measurements from the SDSS, that we will discover a galactic wall that exceeds the size of the Sloan Great Wall? Also, what is larger than the galactic filaments connecting to form the walls? Can somebody please provide the proper topology of what the...

Air within the funnel of a large tornado may have a pressure of only 0.46 atm. What is the approximate outward force F on a 6.2m x 5.5m wall if a tornado suddenly envelopes the house? Atmospheric pressure is 1.013 x 10^5 Pa. Answer in units of N. I know that P= F/A, so F=PA. I tryed just...

Homework Statement A nonconducting wall carries charge with a uniform denisty of 8.g µC/cm2. What is the electric field 7.00cm in front of the wall? Explain whether your result changes as the distance from the wall is varied. Homework Equations I'm still really new, I just...

Hi, I am trying to work out the resistances for the following cavity wall. I am having to work backwards. I have the U value, which is 0.48. The brickwork is 103mm, the insulation in cavity is 50mm, lightweight concrete block is 100mm and plaster board is 13mm. I know total thickness...

Homework Statement A nonconducting wall carries a uniform charge density of 13.62 μC/cm2. What is the electric field 5.7 cm in front of the wall? Answer in units of N/C. Homework Equations Gauss's law...? The Attempt at a Solution Honestly, this bugger's got me scratching my...

I was watching MIT Classical Mechanics Lecture16. On completely elastic collision, (at around 24min), professor Walter Lewin shown that when a tennis ball with mass m and speed v hitting the wall, it bouced back with speed v. (Cut from the lecture) << ...Kinetic energy is conserved. All the...

A woman who weighs 496 N is leaning against a smooth vertical wall. Find Fx= 0= -F Wall = Gx Fy= 0= Gy- Fgwoman (a) the force FN (directed perpendicular to the wall) exerted on her shoulder by the wall T= 0= -Fgw*sin30* ((1.1+.4)/2)- Fgw sin 30 (1.1) + F wall cos 30 (1.5)...

Homework Statement 4.60×1023 nitrogen molecules collide with a 20.0cm^2 wall each second. Assume that the molecules all travel with a speed of 450m/s and strike the wall head on. What is the pressure on the wall in pascals (Pa)? Homework Equations p=(1/3)*(N/V)*(m*v_rms^2) where...

Homework Statement A folding catwalk of uniform density and length 3r is attached to a wall by a hinge. At the other end it is supported by a cable which makes an angle of θ above the horizontal. If a person of mass m stands a distance r from the wall what is the tension, T, in the support...

Homework Statement A horizontal force of 12 N pushes a 0.5-kg block against a vertical wall. The block is initially at rest. If us = 0.6 and uk = 0.8, which of the following is true? (a) The frictional force is 4.9N (b) The frictional force is 7.2N (c) The normal force is 4.9 (d) The block...

The wind in a severe storm is blowing 30 ms perpendicularly to the wall of a large barn of area 80 m2. Calculate the pressure exerted on it, assuming that the air density is 1.3 kg m3. I am quite new to this unit so i really have no idea what to do. Any help apreciated!

Homework Statement A tennis ball of with a mass of .045 kg and speed of 25 m/sec strikes a wall at an angle of 45 degrees and rebounds with the same spped at 45 degrees. What is the impulse given the wall? Homework Equations I= pf-pi/t The Attempt at a Solution I= mv-mv/t...

Hopefully I posted this in the right place. The setup is standard - A ladder 10 ft long rests against a vertical wall. The bottom of the ladder slides away from the wall at a rate of 1 ft/sec. If we let y be the vertical distance and x the horizontal distance, we use the Pythagorean theorem...

A 425 g ball with a speed v of 6.5 m/s strikes a wall at an angle of 30° and then rebounds with the same speed and angle. It is in contact with the wall for 9.0ms. (a) What is the impulse on the ball (take positive as down in the figure)? b. What is the average force exerted by the ball on...

Homework Statement A ladder 10 ft long rests against a vertical wall. If the bottom of the ladder slides away from the wall at a rate of 1.3 ft/s, how fast is the angle between the ladder and the ground changing when the bottom of the ladder is 6 ft from the wall? Evaluate your answer...

Homework Statement http://i450.photobucket.com/albums/qq230/JJBladester/06_p51.jpg?t=1223753179 The 2.0kg wood box in the figure slides down a vertical wood wall while you push on it at a 45 degree angle. What magnitude of force should you apply to cause the box to slide down at a constant...

Homework Statement A 0.13 kg meter stick is held perpendicular to a wall by a 2.7 m string going from the wall to the far end of the stick. (a) Find the tension in the string. (b) If a shorter string is used, will its tension be greater than, less than, or the same as that found in part (a)...

Consider an isolated system of two ideal, identical gases in thermal equilibrium. Gas A is occupying a volume A, separated by a wall from volume B, where gas B resides. They are in thermal contact. The volumes are the same, so are the pressures and temperatures, and it follows that the number of...

Homework Statement A 12 N horizontal force F pushes a block weighing 5.0 N against a vertical wall. The coefficient of static friction between the wall and the block is 0.60, and the coefficient of kinetic friction is 0.40. Assume that the block is not moving initially. (a) will the block...

Homework Statement A wedge with an inclination of angle theta rests next to a wall. A block of mass m is sliding down the plane, as shown. There is no friction between the wedge and the block or between the wedge and the horizontal surface. (Intro 1 figure) what is the magnitude of the force...

A man of height 2h stands in the middle of a room of length 6h. The height of a wall is 4h. What is the minimum length of a mirror to be placed on the wall in front of the man so that he can see the entire wall behind him?

Homework Statement King Arthur's knights fire a cannon from the top of the castle wall. The cannonball is fired at a speed of 45m/s and an angle of 32degrees . A cannonball that was accidentally dropped hits the moat below in 1.4s . a) How far from the castle wall does the cannonball hit...