Wall Definition and 735 Threads

Homework Statement A 9 N horizontal force F pushes a block weighing 13.0 N against a vertical wall (Fig. 6-21). The coefficient of static friction between the wall and the block is 0.62, and the coefficient of kinetic friction is 0.42. Assume that the block is not moving initially...

"September 23, 2008 Price-Anderson's Blank Check Nuclear Power Liabilities Dwarf Bush's Wall Street Bailout By HARVEY WASSERMAN http://www.counterpunch.com/wasserman09232008.html Is the author correct that US taxpayers are shoulding the cost of insuring the nuclear power utilities...

I'm glad that I'm already in graduate school. Thousands of wall street employees are going to be laid off this year as all these companies go under. I bet most of them will be fairly recent college graduates from prestigious undergraduate institutions. Probably, many of them are going to be...

Motion Problem! Homework Statement The Attempt at a Solution Okay, so I got number one (6.36904) but I'm having real trouble getting the angle w.r.t the wall. At first I thought of taking the t (from )[/URL] then multiplying it by the acceleration to get the y component of the...

Homework Statement The wall crane in Fig. 3 supports a load of 800 N. Determine the horizontal and vertical components of reaction at the pins A and D. Also, what is the force in the cable at the winch W? http://img182.imageshack.us/img182/992/tutorialse0.jpg...

http://extras.mnginteractive.com/live/media/site297/2008/0808/20080808_051413_wall_arch_before-after-1_300.jpg http://www.sltrib.com/news/ci_10142089?source=rss "Wall Arch, one of the most accessible major arches in the Devils Garden area of Arches National Park, collapsed sometime Monday...

[b]1. a person whose eyes are H=1.82m above the floor stands L=2..11m in front of a vertical plane mirror whose bottom edge is h= 49.5 cm above the floor, as seen in the figure below. what is the horizontal destance x to the base of the wall supporting the mirror of the nearest point on the...

Homework Statement A 3.00 Kg steel ball strikes a wall with a speed 10 m/s at an angle of 60 degrees with the surface. It bounces off with the same speed and angle. If the ball is in contact with the wall for 0.20 s, what is the average force exerted by the wall on the ball? Homework...

Homework Statement We have waves propagating in the air. First part asks for a traveling wave solution in the x direction , given a wave length 2pi and amplitude 3m. I have obtained u(x,t) = 3 cos ( x - 345t). The question then asks what happens if a wall is placed at x=0, what is the form of...

Hello, A very basic question, with a bit of confusion. a ball hitting a wall which is not moving with velocity v in an elastic collision has its momentum conserved, opposite velocity; -v. if the ball is to collide with a wall which has a velocity -v, equal speed towards the ball, what is...

Hello, I have a question. I have a pool ball mass M and radius R, that hits the pool table wall, at speed V0, angular speed W0 at an angle alfa0, and then goes away with an angle alfa1, speed V1 and angular speed W1. If the ball wasn't spinning then I think it would be easy to solve with...

electromagnet that plug into wall outlet? I am working on a project for science and and trying to make an electromagnet that will plug in a normal wall outlet (120v ac). I have been searching the internet for a way to do this and have found out very little. I am on a lower budget and want to...

fully developed flow liquid of dynamic viscosity 2.9x10^-3 Pa.s and relative density 0.9 in horizontal pipe of diameter 12mm, length of pipe=200mm and mean velocity is 0.5m/s To find the wall shear stress, i used τ=μ.du/dy = (2.9x10^-3)(0.5/0.012) = 0.121Pa The answer is 0.968Pa, where am...

Homework Statement A rubber balloon is rubbed against a wall and then sticks to the wall. This is because 2. multiple choice a. the balloon and the wall exchange charges through contact b. electrons hop back and forth between the balloon and the wall c. the balloon induces an...

cant find an equation for this one.. there is no theta soo i don't know what to do A uniform ladder whose length is 5.8 m and whose weight is 380 N leans against a frictionless vertical wall. The coefficient of static friction between the level ground and the foot of the ladder is 0.54. What...

Homework Statement Total mass = 260 kg Coefficient of Friction = 1.00 r = 4 m gmax = 4 g a) Find the minimum speed to keep the rider on the wall of death. b) Find the maximum speed inside the wall of death of the motorcycle based on gmax Homework Equations \mu x...

1. A ladder leans up against a wall. If the ladder is not to slip, which one of the following must be true? a.friction between the ladder and wall must not be zero b.friction between the ladder and floor must not be zero c. both a and b d. either a orb e. neither a or b 2. net force...

Homework Statement a 250 g ball with a speed v of 6.6 m/s strikes a wall at an angle θ (the angle between the wall and the path of motion) of 30° and then rebounds with the same speed and angle. It is in contact with the wall for 6 ms. What is the impulse on the ball from the wall...

I am trying to imitate the Airhog zero gravity climber one of these http://www.gmhummer.com/forums/showthread.php?t=111 can someone please help me regarding derieving equations for the suction pressure required and regarding selection of motors for driving suction fans. the toy...

Homework Statement A cylin drical con crete sil o is 4m in diameter and 30m high. it consists of a 6000kg concreet base and a 38000kg concrete cylindrical concreete walls. locate the center of mass of the silo (A) when it's empty and (B) when it is two thrids full of silage whose density is...

I cannot find this in my book and i cannot wrap my brain around it...i am more of an analytical person... The question is-A negatively charged balloon is sticking to the wall. Does this mean that the wall is positively charged?Explain.Eventually, the balloon falls down. Explain why. The...

The weight of the block in the drawing (SEE ATTACHMENT) is 64.4 N. The coefficient of static friction between the block and the vertical wall is 0.580. (a) What minimum force is required to prevent the block from sliding down the wall? (Hint: The static frictional force exerted on the block...

Here is the question: The Wall of Death in an amusement park is comprised of a vertical cylinder that can spin around the vertical axis. The radius of the cylinder is 3.5 m and the coefficient of static friction between the rider and the wall is 0.32. Find the minimum number of revolutions per...

I was wondering if it was possible to construct a certain device. There would be a speaker on one side of a wall generating a certain frequency, and on the other side a receiver that would give an image of what was in the wall, such as cabling, studs, etc. I'm sure the technology exists, but I...

a block of mass 4.8 kg is pushed up against a wall by a force F that makes 37 angle with the horizontal. the coefficients of static and kinetic friction are 0.2 and 0.1 respectively. the magnitude of the force F in N that makes the block just about to slip down: wut i did is: F sin...

Homework Statement A uniform sphere of mass m and radius r is held in place by a massless rope attached to a frictionless wall a distance L above the center of the sphere. Find (a) the tension in the rope and (b) the force on the sphere from the wall. Homework Equations net torque = 0...

please help me... I can't find the "NUCLEI WALL" it says I must decribe the structure from the fungi and Include the nuclei wall but I can not find it anywhere as well not on the INternet or on books... Maybe someone could helpp me... And the other question is I must Include the...

Homework Statement A uniform ladder of length L and weight w is leaning against a vertical wall. The coefficient of static friction between the ladder and the floor is the same as that between the ladder and the wall. If this coefficient of static friction is μs = 0.500, determine the smallest...

I have encountered some problems with this exercise: A ladder is leaning against a wall, it will slide due to its weight down the wall and along the floor. I am supposed to determine the time at which the ladder looses contact with the wall, but how? :S

Homework Statement http://img90.imageshack.us/img90/4989/scanuy8.png http://img125.imageshack.us/img125/8163/fbdzh7.png The Attempt at a Solution Been working on this one for at least an hour now =/ n_{1} is the normal force of the wall on the ladder n_{2} is the normal force of...

dear all, i am working on a problem, but not having found the solution yet. i have a wall section (in a 2D x-y plane) on which spherical balls hit and get reflected. i know the x-velocity and y-velocity of the particle when it hits the wall. i need to calculate the impact (incident)...

Homework Statement a 8kg steel ball strikes a wall with a speed of 11.7 m/s at an angle of 35.3 degrees with the normal to the wall. it bounces off with the same speed and angle as shown in the picture. http://img405.imageshack.us/img405/7733/asdfkf7.jpg If the ball is in contact with...

Homework Statement A 10m ladder whose weight is 180N is placed against a smooth vertical wall. A person whose weight is 652N stands on the ladder a distance of 3.2m up the ladder. The foot of the ladder rests on the floor 5.7m from the wall. What is the force exerted by the wall? What is the...

1. Homework Statement A machine designed for quality testing in a handball factory propels the 0.15kg balls toward a wall with a velocity of 9.5m/s at an angle of 60 deg frome the normal to the wall. A typical ball rebounds at 70 deg from the normal at a speed of 9.0m/s. The impact point of...

Homework Statement Homework Equations \SigmaFi = 0 \Sigma\tau = 0 Nw = force of the wall Ff = Frictional force \mu = frictional coefficient T = Tension The Attempt at a Solution \SigmaFx = Nw - Tsin(30) = 0 \SigmaFy = -mg + Tcos(30) + Ff = 0 \Sigma\tau = (R/2)mg -...

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. Find the magnitude, F_ww, of the force that the wall exerts on the...

Homework Statement M, a solid cylinder (M=1.67 kg, R=0.137 m) pivots on a thin, fixed, frictionless bearing. A string wrapped around the cylinder pulls downward with a force F which equals the weight of a 0.670 kg mass, i.e., F = 6.573 N. Calculate the angular acceleration of the cylinder...

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. http://session.masteringphysics.com/problemAsset/1010942/31/MFS_cf_11.jpg...

Homework Statement A rocket is fired at a speed of 75.0 m/s from ground level at an angle of 60.0º above the horizontal. The rocket is fired toward an 11.0m high wall, which is located 27.0m away. By how much does the rocket clear the wall? Homework Equations y=v[SIZE="1"]ot-1/2gt^2...

Homework Statement a 120kg ball moving at 18m/s strikes a wall perpendicularly and rebounds straight back at 12m/s. after the initial contact, the centre of the ball moves 0.27cm closer to the wall. Assuming uniform deceleration, show that the time of the contact is 0.00075s. How large an...

Homework Statement Question: A stream of water from a hose is hitting a window. The window is vertical, the stream is horizontal, and the water stops when it hits. About 20cm(cubed), that is 20g, of water with speed 1.5 m/s strikes the window each second. Find a) the impulse on the window in...

Homework Statement A frame hung against a wall is suspended by two wires attached to its upper corners. If the two wires make the same angle with the vertical, what must this angle be if the tension in each wire is equal to 0.75 of the weight of the frame? (Neglect any friction between the...

Homework Statement Consider a smooth vertical wall against which a block is placed.Another block is also placed in contact with the earlier inner block.An external force F is acting horizontally on the outer block towards the wall.There is friction between the two blocks,but no friction...

I saw a similar thread on this issue - so I'm cross posting this forum with a builders forum as well - as I'm very worried about this, and am seeking input ASAP... I apologize if this is off-topic - but I really need some advice ASAP... Last week I cleared an area out next to a fence that...

I can think of two principles which explains why I can't lesuirely walk through a concrete wall. The HUP and Pauli's exclusion principle. Which one contributes more?

As I understand it: In a regular cylindercal soleniod the winding starts at one point(top) and winds down to the other side(bottom) of a cylindercal core. Once the wind reaches the bottom, the wire returns back to the top and so forth, until the desired winding is achieved, let's say 10 layers...

Homework Statement A block of mass 2 kg is pushed against a rough vertical wall with a force of 40N , co-efficient of static friction being 0.5.Another horizontal force of 15N is applied on the block in the direction parallel to the wall. Homework Equations Will the block move? If yes...

I need to determine the minimum wall thickness for 1018 CRS for a knife blade. I know the moment, max deflection, greatest safe load, yield strength, MOE, length, density, current wall thickness, etc. However, I can not find a general formula connecting yield strength to wall thickness...

Homework Statement Among many other things, determine if a projectile will clear a wall. I am attempting to make a program to respond with a 'yes' or 'no'. So this is not a specific question, it is more of a general "how is this solved?" question. The known values are initial height...

Can anybody explain how the momentum is conserved in the case of a rubber ball (bounced back),when it was throwned to a wall?