Block Definition and 998 Threads

Homework Statement A 2.8kg block slides over a smooth icy hill. The top of the hill is horizontal and 70m higher than its base. The 70m plateau is 80m from the base of the hill. What is the minimum speed the block must have so that it will not fall into the pit on the far side of the hill...

Homework Statement In a friction lab to determine the static and kinetic coefficient of friction, there is a block on a flat slope attached to a string which pulled down by a hanging mass. The lab question is: Why is it important to make sure that the string attached to the block is level...

I apologize i do not have a picture to show. 1. Homework Statement [/b] A block of mass 250g is at rest on an incline that makes an angle of 30 degrees to the horizontal. The coefficient of kinetic friction between the block and the plane is 0.10. The block is attached to a second block...

Homework Statement The force constant of a spring is 600 N/m and the un-stretched length is 0.72m. A 3.2kg block is suspended from the spring. An external force slowly pulls the block down, until the spring has been stretched to a length of 0.86m. The external force is then removed, and the...

[b]1. What is the acceleration of the 20 kg block if the block is being pulled with a force of 150 N at 60 degrees above the X+ axis and there is a frictional force of 20 N acting on the block? [b]2. F=ma, Fcos(theta). [b]3. I did (150)cos(60)=(20)a ---> 75=20a ---> a=3.75 m/s...

Homework Statement okay this isn't really a question, but i didnt knew where to post it, tell me if it has to be posted somewhere else. a pic of the diagram would help a lot. A block is kept on the top of a wedge of angle alpha, can u explain what all happens, keeping all surfaces...

Homework Statement Homework Equations f = ma The Attempt at a Solution I need help with all parts of this problem, but here are my comments on part a and c: a) the block has its normal force vector pointing up and its weight vector pointing down. the tension of the rope is pulling it to...

Homework Statement Two blocks are connected by a string (through a frictionless massless pully) block 1 is on an inclined plane, while block two is hanging from the other end of the string. m1 = 20kg, theta =53.1, friction between the block and the inclinde is \muk =.4 what is m2 such that...

This is more a question about how the problem is written, rather than a question about how to do the problem Why do they ask for tan γ in terms of d/l and h/l, rather than d and h? Is there some relation that I'm just not seeing? I'm pretty sure I know how to do the problem in terms of d...

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 6 kg block rests on a horizontal table, attached to a 5 kg block by a light string as shown in the figure. The acceleration of gravity is 9.81 m/s2 . A) What is the minimum coefficient of static friction such that the objects remain at rest? I already got part A which is 0.833, but...

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Homework Statement A block is at rest on a plank whose angle can be varied. The angle is gradually increased from 0 deg. At 25.7°, the block starts to slide down the incline, traveling 3.50 m down the incline in 1.50 s. Calculate the coefficient of static friction between the block and the...

Homework Statement 4 questions: 1. A block of mass M=2.6 kg is dragged over a horizontal surface by a force F=22.0 N. The block is displaced a distance d=10.0 m, the friction force Ff is 3.1 N. What is the weight of the block in Newtons? Use 10 m/s2 for g. 2. A block of mass M=1.0 kg is...

i was solving a problem based on archimedes principle. but got confused whilr determinig the pressure. well the situation was that a block is immersed in water. the height of water column above it is .05m. the blocks side is .02 m and its base area is 25cm^2.and the height of water below the...

Homework Statement Part 1: A 0.1 kg block attached to a spring of force constant 17.2 N/m oscillates with an amplitude of 16 cm. Find the the maximum speed of the block. I solved this part using the equations for angular frequency and max velocity. Part 2: Find speed of the...

Homework Statement A 382 g block is put in contact with a thermal reservoir. The block is initially at a lower temperature than the reservoir. Assume that the consequent transfer of energy as heat from the reservoir to the block is reversible. Figure 20-22 gives the change in entropy ΔS of the...

Homework Statement In a simulation of machinery at a mine site, blocks of wood were used as shown in the following experimental set-up in which the two blocks – A and B – both of mass 15 kg are joined by a string over a frictionless pulley. Block A rests on a frictionless incline of 30º...

Homework Statement A block with mass 10kg rests on a smooth, friction less ramp that is inclined at an angle of 45 degrees with the ground. How much force must be applied in the direction parallel to the ground to prevent the block from sliding down the ramp? IT TURNS OUT THAT THE...

Homework Statement A block with mass 10kg rests on a smooth, friction less ramp that is inclined at an angle of 45 degrees with the ground. How much force must be applied in the direction parallel to the ground to prevent the block from sliding down the ramp? IT TURNS OUT THAT THE...

Hi guys, this is quite an inbetween question , not really homework but still theory. http://img850.imageshack.us/img850/1290/81696653.jpg Came across this diagram and was wondering if the arrow (in blue box) can be ignored ? Quite irritated by it now since I can't be sure how I should...

Homework Statement A 10g bullet strikes and becomes embedded in a 0.200kg block of wood placed on a horizontal surface just in front of the gun. If the coefficient of sliding friction between the block and the surface is 0.4 and the impact drives the block a distance of 8m before it comes to...

Homework Statement Draw a fully labelled block diagram of a 3-bit ‘Flash Encoding’ analogue to digital converter (ADC) and explain how the device converts an analogue voltage into a 3-bit binary number. The Attempt at a Solution anyone know how to do this or have any sources would be...

Homework Statement Homework Equations \sigma = F/A The Attempt at a Solution I understand that I should evaluate the different forms of stress to find different values of the ultimate load. I also understand that I should choose the smallest value among them since anything...

Can someone calculate the weight of the object and what would most likely happen in the following experiment that I have always been curious about: Imagine you have a brand new 52-foot standard refrigerated cargo trailer mounted on a brand new standard heavy duty sleep cab tractor (i.e., an...

Hello, If I have block matrices A,B,C and D all of which are non singular would this relationship hold; my main concern is preserving order of matrix multiplication: if ADB=C then AD=B^-1C D=B^-1CA^-1 D^-1 = (BC^-1A) Also is it okay to assume the inverse of a block...

Hi, I like it here! This lounge it's cozy. It's magic too, because it brings out the best out of scientists. (any mad scientist around? with no sense of humour? :biggrin:) I looked around and I have a question for you: why should a scientist hide his age? Probably now you can...

Hi! This is my first post on physicsforums. I wasn't sure if it belonged here or in the Chemistry forum, but just picked here. I am trying to figure out if my drinking water filter system removes some fluoride from my water. (I know it doesn't remove all as it's not specifically a fluoride...

Homework Statement A block is suspended from a scale and then lowered into a bucket of water. The density of the water is 1 gm/cm3. The initial reading on the scale is 19N and one complete revolution of the scale is a change of 10N. (The block is completely submerged after one complete...

Homework Statement Calculate the coefficient of friction between a fuzzy block and dynamics cart? This is a Lab task so I have all the materials but I don't know where to start. Homework Equations u=ff/fn uk=fk/fn us=fs/fn The Attempt at a Solution I tried using the formulas...

A 45 deg wedge is pushed along a table with constant acceleration A. A block of mass m slides without friction on the wedge find its acceleration. Clue if A=3g then \ddot{y} = g I'm not sure of the forces on the block, if A is parallel to the base of the wedge then what component of A acts...

Ice block on inclined plane-- easy problem! I'm pretty sure I did this correctly, but my answers are different from those given in the back of the book (which our TA warned us were frequently incorrect), so I thought I'd ask you guys if I made any obvious mistakes. Homework Statement A...

A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track (as shown in the figure attached for#007). It leaves the track horizontally, flies through the air, and subsequently strikes the ground. The acceleration of gravity is...

Homework Statement the latent heat of fusion for this metal is 500Cal/kg. The latent heat of vaporization is 600Cal/kg and specific heat of the liquid metal is 500C/kg K. How much heat is needed to melt an 8kg block of this metal when its temperature is exactly at the melting point...

Homework Statement A block of mass m1 = 2.00 kg and a block of mass m 2 = 6.00 kg are connected by a massless string over a pulley in the shape of a disk having radius R = 0.250 m and mass M = 10.0 kg. These blocks are allowed to move on a fixed block – wedge of angle 30.0°, as shown in...

Homework Statement Prove any nxn matrix can be written as in block form N 0 0 B where N is a kxk nilpotent matrix and B is an (n-k)x(n-k) invertible matrix. Need help getting started, or any hints/any help at all would be really appreciated. Thank you!

Homework Statement In which block 106th element belongs? How do we solve such questions?

1. Homework Statement 2. Homework Equations I need to reduce the above block diagram to find the closed loop transfer function This is my solution to the reduction part of the problem: i) Add the feed forward paths; (10 + 10) ii) cascade G(s)2 x G(s)3 , {G(s)2 = 1/1+12, G(s)3= 20/s}...

Hi I would greatly appreciate help on this problem. Homework Statement Ok so here is the problem Homework Equations The Attempt at a Solution I first tried to work out the moments for the block on the ground with no angle to the ground. moments about a = .45(35000*g) -...

Homework Statement A 20-g bullet is fired into a 2.0-kg block of wood placed on a horizontal surface. The bullet stops in the block. The impact moves the block (+ bullet) a distance of 5 m before it comes to rest. If the coefficient of kinetic friction between the block and surface is...

A block m1 with mass 7 kg moves up an inclined plane with an initial velocity v=4.7 m/s. The inclined plane is at an angle of theta = 45 degrees from the horizontal. The coeff. of kinetic friction between the block and the incline is 0.25. What is the block's velocity when it has traveled a...

Homework Statement A .007 kg bullet is fired into a 2 kg wooden block initially at rest on a level surface. The bullet passes through the block and emerges with the velocity of 200 m/s. The block slides .5 m and stops. If the coefficient of the friction between the block and and the surface...

Homework Statement A 5g bullet is fired horizontally into a 0.50kg block of wood resting on a frictionless table. The block, which is attached to a horizontal spring, retains the bullet and moves forward, compressing the spring. The block-bullet system goes into SHM with a frequency of 9Hz...

I am trying to put a lot of data into a matrix to call upon later in plotting. From a masterfile, I need to call on the (:,1) values on x and y, and the (:,2) values in x and y. It is easy to construct a 12x3 matrix to contain all of this information, however when I am plotting I want to call...

Homework Statement A block of mass 12 kg is projected up a frictionless incline with an initial velocity of 8m/s. It just reaches a point B and then slides down again. A) what is the potential energy of the block at B if its potential energy at A is taken as zero? b) what is the...

I'm a bit confused about how the d block elements form coordination complexes. Cobalt for example. It has 7 d electrons. In the +3 oxidation state it has 4 d electrons left (unless it loses its 4s electrons first) so I don't understand why it coordinates 6 ligands. The 6 ligands acting as Lewis...

The following excerpt is taken from a Swiss Federal Nuclear Safety Inspectorate (HSK) publication[1]: “In the year 1988 a large scale crash test was performed at the US Sandia National Laboratory in which a Phantom military jet with a weight of 19 tons was impacted at a velocity of 774 km/h...

1. A 2.3kg wood block hangs from the bottom of a 1.0kg, 1.2m long rod. The block and rod form a pendulum that swings on a frictionless pivot at the top end of the rod. A 10g bullet is fired into the block, where it sticks, causing the pendulum to swing out to a 33degree angle.Homework Equations...