Figure Definition and 590 Threads

Water stands at a depth D=35 m behind the vertical upstream face of a dam of width W=314 m. Find the net horizontal force on the dam from the gauge pressure of the water: I am quite lost here. I thought it would just be F=Pressure*Area =(rho*g*D)(D*W). But that is horribly wrong. What am I...

asymptotes horizontal and vertical f(x)= 2x+3/x+2 f(x)=5x/x^2+1

Homework Statement Please take a look at the attached figure. It is the function f(x,y) = x^2*y in the interval -1 =< x =< 1 and x =< y =< x+2. From the figure, is it correct that the minimum is in f(-1,-1) = -1 and the maximum is in f(1,3) = 3?

6.0221367 is a number rounded to 8 significant figures. In a question, I am asked which of these shows correct rounding off. 6.022 6.0 6.02214 Aren't they all correct? It does not specify to how many figures.

A problem in my textbook shows 25/9(20-y)^2 = 144+(20-y)^2 Then the very next step shows 16/9(20-y)^2=144 Maybe its just me, but I can't seem to figure out the algebra behind this step in the problem, any ideas on where to start? I thought about subtracting/dividing the (20-y)^2 from the...

This figure attached gives the path of a squirrel moving about on level ground, from point A (at time t = 0), to points B (at t = 6.00 min), C (at t = 12.0 min), and finally D (at t = 18.0 min). Both axes are marked in increments of 10.0 m (therefore the diagram is not drawn to scale). Consider...

The rocket, named Saturn V, was used to place humans on the surface of the Moon. It has 3 separate stages with the crew Command Module and Lunar Lander on the top. The first stage has a mass of 2 286 688 kg at launch. The stage was powered by 5 F-1 rocket engines which produced a total of 34 596...

Let's say the mass of an object is given. Then the initial/final velocity of that object. If they also tell you the time for the motion to happen, what formula could you use to figure out the power created?

Homework Statement y ' [x] = xy y[0] = 1 Homework Equations none The Attempt at a Solution I posted this somewhere else and 2 people got the answer is y = e^x I am getting something else though. I get up to here: dy/dx = xy 1/y dy = x dx ln y = (x^2)/2 + C...

Okay, here's my favorite brain teaser. Sorry if an equivalent version has appeared here before. On a remote island somewhere there was an ancient country whose population consisted of 200 people with green eyes and 800 people with blue eyes. The citizens of this country were all happy and...

Homework Statement The object in Figure P23.50 is midway between the lens and the mirror. The mirror's radius of curvature is 20.4 cm, and the lens has a focal length of -16.9 cm. http://www.webassign.net/sf5/p23_54.gif Figure P23.50 A. Considering only the light that leaves the object...

Hi all. Please kindly read the figure below and see if you can help me. Thanks.

1. I read on my physics book that "zeros located at the end of a number are not significant if they are not followed by a decimal point." it also gave an example: 3000 K, in this case, there is only 1 significant figure. However, the number 93,000,000 m, on my book it says only the first five...

I've been trying to figure this out for a while, but I can't find the right substitution: \int \sqrt{\frac{x-1}{x(x+1)}} dx Anyone able to help me out? It's driving me crazy.

Homework Statement How many revolutions per minute would a 15m diameter Ferris wheel need to make for a person to feel 'weightless' at the topmost point? Homework Equations F= mv~2/r - mg v = 2pi r/ T The Attempt at a Solution I get 8.57 m/s using the equation F= mv~2/r - mg I...

To start things off i am using DSC (Dipsersion Strenghtened Copper) 99.58% copper 0.19% Aluminum Oxide 0.16% Oxygen Less than .01% Iron Less than .01% Lead max tensile is about 10 breaking pounds or 88ksi i think for...

Homework Statement When 2 simple harmonic motions are applied to a particle at right angles to each other having time periods in the ratio 1:2, you get a figure of eight. When the phase difference is (pi)/4,3(pi)/4,... you don't get a perfect figure of eight.Can it be called a distorted eight...

Meteorities are rocks from space that fall to earth. One such rock was 41m in diameter and landed in Arizona. it had so much kinetic energy on impact that it made a crater 228m deep and 1219m in diameter. Some scientist suggest that we should invest money to locate and track these space rocks...

During construction of a hotel, all the parts of the building that are raised above ground have gravitational potential energy relative to the ground. if after many years the hotel is to be demolished all of this energy can be used to force the building to collapse on itself. if u r the engineer...

Hey everyone, I am having trouble finding out the equation I need. Could someone please walk me through finding out the Speed of a Water-Tube if it is being whipped behind a boat on a 75ft rope, and the boat is traveling at a speed of 60mph? Any help would be greatly appreciated, I've been...

Question: A ball of mass m is suspended from a string of length l. A lump of clay of mass 3m is thrown horizontally at the ball w/ a speed of v0 making a direct hit and sticking to it. Find the speed of the combined object right after the collision, and how high it rises. Answer: 3/4vo...

Homework Statement Was performing the online "reading questions" for my Physics 2 course. And I came to this question. "A wave is not a material thing but a disturbance moving through a medium. The way that it propagates is that every part of the medium it encounters begins to vibrate...

Homework Statement You dissolve an unknown quantity of weak acid HA into 50 mL of water. It only takes 1 mL of 5 M NaOH to completely neutralize the acid. The Ka of the acid is 3.2 x10^-4. What is the pH at the endpoint?Homework Equations Ka * Kb = Kw pH + pOH = 14 p(of whatever) = -log(of...

Cant figure out how to do this problem?? A person pushes a 14kg lawn mover at constant sped with a force of 88N directed along the handle, which is at an angle of 45 degress to the horizontal. (a) draw the Free-body diagram showing all forces acting on the mower. (b) Calculate the horizontal...

Hey guys. I'm wondering how to figure a grade. And if you can show me steps, so I can always be up to date on figuring it. Ok, he says this...3 exams at 22% each, final at 22% and classwork at 12% On exam 1 I got a 78/100pts. On homework, I've gotten 156/156pts. This is...

Does gravitational acceleration g vary with distance, mass, size of the object?

Sin contest question from 2003-- Can't figure this question... it's exam review! help the questions is: A kid is 5m from a fence that is 4 m high. He throws a ball @ 45 degrees from the horizontal which just grazes the fence. How far beyond the fence does the ball land? You may assume that the...

A boy throws a rock horizontally 12 m/s at a pigeon on a fence 5m away. Unfortunatley the rock the missed. By how much did the rock miss? I ve got my kinematic stuff down pat, but I just had no idea how to go about this problem. thanks for any help.

1. Homework Statement - Consider a copper wire 1 mm in diameter providing the power to run an appliance drawing 4.8 kW at 12 V. Assuming no heat radiated away from the wire while the currecnt flows, (a) what will the temperature of the wire be after the current has run for 1 second through...

We just started talking about it at school, and naturally i hav no idea what the teachers talking about! I was wondering if there are any good websites/videos online that explain it? Id be asking for a bit too much for a direct explantion from the physics buffs here :D cheeeers.

Greetings, On the board today in my calculus class, the teacher had a word problem that has stumped some other teacher, and wanted to see if we could figure it out (I realize this is the PREcalculus board, but I'm sure calculus isn't required to solve the problem). I don't remember it word...

How should I be going about this problem? Here is the question, diagram, and my work: A 50-story building is being planned. It is to be 200m high with a base 40m by 70m. Its total mass will be about 1.8X10^7 kg and its weight therefore about 1.8X10^8 N. Suppose a 200km/h wind exerts a force of...

A figure skater is spinning at a rate of 1.40 rev/s with her arms outstretched. She then draws her arms into her chest, reducing her rotational inertia to 68.0% of its original value. What is her new rate of rotation? I am having trouble starting this problem. I know that (I)(alpha)...

In Figure Skating, when the players are rotating, there’s a way to slow him/herself down, do you know what’s that? Using the knowledge of angular momentum, analyze qualitatively why he/she can achieve such effect?

The drawing shows a human figure approximately in a sitting position. For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 41.5 kg) with a center of mass...

Ok, let me see if I can explain this well enough. There's a horizontal circular rod governing the motion of a collar having mass .75kg. The coefficient of kinetic friction is .3 and the collar is given an initial speed of 4 m/s starting at theta=0. I need to determine the arclength the collar...

A small ball bearing having a mass of 50.0g was dropped in a graduated cylinder filled with a thick but clear motor oil. At the point shown by the diagram, this ball bearing was moving at a sonstance velocity of 4.5cm/s.Use This information to calulate the frictional force of the oil on the ball...

Hello everyone. I've been looking at examples and I can't seem to see what they are doing. For example, the book has: Suppose that d1, d2, d3 ... is a sequence defined as follows: d1 = 9/10, d2 = 10/11. dk = dk-1 * dk-2 for all inegers k >= 3. Prove that dn =< 1 for all...

WHAT DID EACH OF THESE WOMAN BUY IN THE FOLLOWING SCENARIO AND HOW DID YOU ARRIVE AT YOUR ANSWER? Ms. Adams, Ms. Baker, Ms. Catt, Ms. Dodge, Ms. Ennis, and Ms. Fisk all went shopping one morning at the Emporium, Each woman went directly to the floor carrying the article that she wanted to...

I bet you can't figure this one out! Ive been working on this problem for extra credit in one of my classes all morning and its driving me nuts. The problem is "you are given 12 pennies, they all weight exactly the same except one, your a given a balance scale and need to figure out if the...

The problem is this A cable television firm presently serves 5000 households and charrges 20 dollars per month. A marketing survey indicates that each decrease of 1 dollar in the monthly charge will result in 500 new customers. Let R(x) denote the total monthly revenue when the monthly...

This chapter is working with negations of Quantified statements. True or False. All the occurrrences of the letter u in the title of this book are lower case. Justify your answer. I said false, because they arn't being clear when they say "this" If even 1 book doesn't have a lowercase...

Harry the painter swings year after year from his bosun's chair. His weight is 500 N and the rope, unknown to him, has a breaking point of 300 N. Why doesn't the rope break when he is supported as shown to the left below? One day Harry is painting near a flagpole, and, for a change, he ties the...

Um hello, I am new to this forum and still don't understand everything very well but i need some help. I've been doing revision over the new topic we've been learning in high school physics about electrical forces and fields and we've been spending most of the time doing questions about columbs...

in a rutherford gold experiment, alpha particles with sharge +2e and a kinetic energy of 7.7 Mev were beamed at gold foil. the nuclius of a gold atom contains 79 protons, giving it a charge of +79e. What is the closest distance that an alpha particle can get to a gold nucleus when it approaches...

How did Newton arrive at the conclusion that the force of gravity is directly proportional to the product of the masses of two objects, and inversely proportional to the square of their distance? I know that he was the first to realize it's gravity that keeps the planets in orbit, but what...

Hello, I am having trouble with this integral, I don't know how to solve it. integral(x * cos(x))dx I tried it in the calculator and it gave me the integral back, and I don't know what method of integration to use to figure it out. Well if anyone has a solution that would be great, thanks.

Ok, I was trying to think of a first problem/question to pose to everyone for my first pose, so here it goes... (there's a lot of questions and topics already posted, so someone may have already asked this) Situation: One Antimatter Proton and One normal matter proton are on a collision...

I messed up in the lab a week or so ago, and was unable to do the lab properly. There was no time to restart so I am missing a crucial piece of data. I need to know the mass of my calorimeter + the mass of a solution. I know the mass of the calorimeter, and I know the mass of the first...

what is the proper method for finding the average of an integral? For example, the question I'm trying to answer is this: "Find the average value of the function f(x) = 4 - x² over the interval [-2, 2]." Now the answer is suppost to be 8/3. But I keep getting an answer of -11/3 no...