Homework problem Definition and 419 Threads

Homework Statement A stockroom worker pushes a box with mass 11.2 kg on a horizontal surface with a constant speed of 3.50m/s. The coefficient of kinetic friction between the box and the surface is .20. What horizontal force must the worker apply to maintain the motion? Homework Equations...

Hello, I have solved the following problem but my answer does not matched with the answer which is written in the book. My answer is 32 m/s but the answer of the book is 37 m/s [PLAIN]http://img842.imageshack.us/img842/6706/projectile.png Could anyone please show me where my mistake is...

Homework Statement A person flying east on September 21 at sunrise hears the time is 2:00PM Greenwich Time. Flying hour after hour at 105 MPH over nothing but water see the the sun set in only ten hours since sunrise. Along what line of latitude have they been flying. Homework Equations...

Homework Statement Well I don't think my teacher explained this very well so I need some help.. Thank you in advance. 26.) A person pushes a 14.0-kg lawn mower at constant speed with a force of F = 88.0N directed along the handle which is at an angle of 45.0(degrees) to the horizontal. a)...

Homework problem stated this: Let S={0,1,2,3,4,5,6} let * be defined by x*y=max(x-y,0) is it commutative, associative, does it have an identity and inverse? help please! I put that yes it is commutative and yes for associative, but I'm not to sure they are right becuase the 6 is...

Homework Statement [PLAIN]http://img194.imageshack.us/img194/2062/57916122.png Homework Equations F_{gravitational}= \frac{MmG}{r^2} F_{centrifugal}= \frac{mv^2}{r} The Attempt at a Solution I got this: dF_{centr} = dF_{grav} \longrightarrow \frac{dm \cdot v^2}{R+x} =...

Homework Statement An airplane flies 142 mi/hr with respect to the air. On this day, the air is moving at 52 mi/hr due north with respect to the ground. What would be the velocity of the plane with respect to the ground,vpg, if the plane were pointed in each of the following directions? How...

This questions has been bothering me for quiet a while Does lim_{x\rightarrow \infty} f(x)=0 \Rightarrow lim_{x\rightarrow \infty} f'(x)=0 if so can you please post a proof because its giving me a headache. If not would it please be possible for you to give me a counter example. Many thanks

A blade parallel faces is 5 mm thick. Taken to a microscope it appears that, to pass on the focus of a surface point to a point on the underside of the blade should move the cannon from the microscope 3mm. What is the refractive index of the material it is made the blade? 5/3 Thx EDIT: Sorry...

Homework Statement State that is either true or false The span of an empty set is empty set Homework Equations n/a The Attempt at a Solution from definition, when you span a subset of vector space, the subset must be non-empty. so, how should i answer this question? should i answer...

Homework Statement if a and b are odd integer, then 8 l (a2-b2) Homework Equations n/a The Attempt at a Solution if a=b, clearly, 8 l (a2-b2) if not, now, I'm not sure how to continue should i varies b, and make a fixed, then varies a, and make b fixed, is that really the...

Homework Statement the problem is attached Homework Equations The Attempt at a Solution pls giv me the answer only

I have read the entire chapter in my book and have searched the internet and I still have no idea where to even begin. HELP! 4. a.) Explain the significance of a probability of 1.0 and of a probability of 0.0. b.) Calculate the probability for an event to occur if 420 events have...

Homework Statement ∫cos(x)sin^6(x)*dx Homework Equations The Attempt at a Solution u=sin(x) then du should be -cos(x) according to the integral tables? -∫u^6*du = -u^7/7 -sin^7(x)/7+c yet my book and calculator tell me the answer is positive. How?

Hey guys I am completely stuck and have no idea where to start. Help? Homework Statement Car A and Car B collide in an elastic collision. Use the data in the table shown to calculate the maximum compression of the car bumpers. The spring constant of the car bumper is 60 000 N/m. Assume...

Approximate 1.58800 - (1.5402 sqrt(-1))

Homework Statement Three people register for a room; the desk clerk charges them $30. The manager returns and says this was on overcharge, instructing the clerk to return $5. The clerk takes five $1 bills, but pockets $2 as a tip and returns only $1 to each guest. Of the original $30...

Homework Statement A 100 mm cube has a thin and rigid wire inserted 20 mm from each of two adjacent edges ,as shown.The cube contains a sphere that is not cut by the wire .What is the largest possible radius ,to the nearest mm, of the sphere that just touches the wire? Homework Equations...

Homework Statement Prove that the set of rational numbers with the relative topology as a subset of the real numbers is not locally compact Homework Equations none The Attempt at a Solution I am totally confused and want someone to give me a proof. I have looked at some stuff...

Homework Statement The equation \frac{dy}{dx} = A(x)y2+B(x)y+C(x) is called a Riccati equation. Suppose that one particular solution y1(x) of this equation is known. Show that the substitution y = y1+\frac{1}{v} transforms the Riccati equation into the linear equation \frac{dv}{dx}+...

Homework problem: "Consider the transformation ... " Homework Statement 1. Consider the transformation x=u2+v2 and y=u3+v3. (a) Check that the Jacobian equals 0 on the line v=u and on the u-axis and on the v-axis. (b) Show that the transform of the line v=u is the curve 2y2=x3, and...

Homework Statement Evaluate ∫ -2 to 2 (x + 3)(4 - x^2)^1/2 dx by writing it as a sum of 2 integrals and interpreting one of those integrals in terms of an area. Homework Equations None. The Attempt at a Solution ∫ -2 to 2 (x + 3)(4 - x^2)^1/2 dx = ∫ 0 to -2 (x + 3)(4 - x^2)^1/2...

Homework Statement The atomic mass of gold-197 is 196.96654 u. How much energy is required to completely separate the nucleons in a gold-197 nucleus? Homework Equations E = 196.96654 u x 931.5 The Attempt at a Solution I did the above calculation and got 1.83e5 MeV but I am...

What would the integral of ln|x| be.

How do I integrate the following: \int_0^\infty r e^{-ar} \sin{(Kr)} dr i tried writing r e^{-ar} = -\frac{d}{da} e^{-ar} and using integration by parts but i couldn't get anywhere. any ideas?

Homework Statement I got that|G|=40 and |Z(G)| contains an element of order 2. From Lagrange i know that the order of Z(G) must divide |G| and be a multiple of 2. I am able to do all the cases by the G/Z theorem accept for 1 case. This is the case where |Z(G)|=2. Then I get |G/Z(G)| =20, and I...

Homework Statement Please I am just going to list the question then show my solving, It is a physics question but I need help on integration, on parts of the question, thank you quesiton: A particle in the infinite square well, (i.e V(x) = \left{ \begin{array}{ccc} 0 & \textrm({ if 0 <= x <=...

Homework Statement This is a two part question. the graph is a force as a function of displacement first mass of an arrow= .002 kg marker= .01154 kg delta x= 0.7 while x = 0.15. the coordinate points are (0,0) and (0.15, 9.5) 1. Find K 2. Find elastic energy (Ue) 3. Find speed for...

I want to verify the procedure of finding .\Gamma(n+p+1). with p =-ve. This is usually found in Bessel's equation. It is well talked about if p=+ve. But books I have don't even talking about in general how to find the series representation when p=-ve. I worked this out and I want to verify with...

how can we prove that lun x is continuous over (0, \infty )? Provided that we define : lun x =y <=> e^y =x?

Homework Statement There are 2 nichrome wires P and Q are connected in series to battery of emf , V . Both P and Q are of same length bu the diameter of wire P is bigger than that of wire Q . When wire P and Q glow steadily , which one would glow brighter ? Homework Equations The...

Homework Statement Consider the sequence. http://www.webassign.net/cgi-bin/symimage.cgi?expr=a_n%20%3D%204%20n%20%2B%201%2Fn (a) Determine whether the sequence is increasing, decreasing, or not monotonic. (b) Is the sequence bounded? Homework Equations The Attempt at...

Homework Statement See the picture for the situation of the problem. I'm told that any ray starting from S and getting through the "Cartesian Oval" reach point P. I must show that the equation of the interface curve is l_0n_1+l_i n_2=K where K is a constant. So far I've showed that...

When a dielectric is inserted between the plates of a parallel plate capacitor , what would happen to its charge , Q and electric potential , V as compared to when there is no dielectric ? My thoughts are the presence of dielectric cause the resultant electric field to decrease , and from...

Homework Statement 1. What is the kinetic energy in joules of a 950-lb motorcycle moving at 50 mph ? 2. If the speed of the motorcycle changes from 50 mph (with kintic energy K1) to 25 mph (with kinetic energy K2), what is the ratio of K1 to K2? Homework Equations 1. KE=1/2mv2...

Homework Statement Hello, I am a French teacher who teaches physics in English. I've proposed to my pupils this work about the tides.http://vfsilesieux.free.fr/2deeuro/Thetides.html" I would very much enjoy any kind of correction (vocabulary, grammar, ideas) to improve the quality of this...

I wanted to make sure I did this problem correctly. The problem is: A particle moves along a straight line and its position at time t is given by s(t)=2t^3 - 21t^2 + 60t where s is measured in feet and t in seconds. Find the velocity of the particle when t=0. I took the derivative of...

Homework Statement \sum^{n}_{r=1}(\lg \frac{2^r(r+1)}{r})=\sum^{n}_{r=1}[\lg 2^r+\lg (r+1)-\lg r] Homework Equations The Attempt at a Solution i found the answer to be (2^n-1)\lg 2 +\lg (n+1) Am i correct , or it can be further simplified ? Thanks .

Homework Statement An inclined plane at 30.0° is 4.9 m long. A book which has a coefficient of kinetic friction with the inclined plane of 0.16 is placed at the top and immediately begins to slide. How long will it take for the book to reach the bottom of the incline? Homework Equations...

Homework Statement Find inf{|x-pi|:x\inQ} Homework Equations The Attempt at a Solution I was thinking that the greatest lower bound must be 0, but that seemed a bit simple. Is there any justification I have to give for this? Any help would be much appreciated. Cheers. :)

Homework Statement A package of mass m hangs from a short chord that is tied to the wall via cord 1 and to the ceiling via cord 2. Cord 1 is at an angle 40 degrees with the horizontal cord two is at an unknown angle. -For what value of the unknown angle of cord two is the tension minimized...

1. Figure 7-30 shows an overhead view of three horizontal forces acting on a cargo canister that was initially stationary but that now moves across a frictionless floor. The force magnitudes are F1 = 2.28 N, F2 = 4.54 N, and F3 = 8.24 N, and the indicated angles are θ2 = 51.6° and θ3 = 35.8°...

Homework Statement http://www.public.asu.edu/~gbadams/f06/F424.gif Block1 = 2kg Block2 = 3kg Block3 = 4kg What is the force on block 1 by block 2 Homework Equations F=ma The Attempt at a Solution i know this is easy but i can't figure it out. i found the acceleration of the 3 blocks...

1. If the Earth had a net surface charge density of 1.0 electron per square meter a) what would be the total charge on the Earth's surface? b) what would be the electric potential and c) what would be the electric field, just outside the Earth's surface? Attempt: I tried using...

Homework Statement A particle P of mass m moves on a smooth, horizontal table, and is attached to a light, inextensible cord that is being pulled downward by a force F(t) as shown. The differential equations of motion are -T = m(r(double dot) - r*(theta(dot))^2) 0 = r*(theta(doubledot)) +...

Homework Statement A 3-lb collar can slide on a horizontal rod which is free to rotate about a vertical shaft. The collar is intially held at A by a cord attached to the shaft. A spring constant of 2 lb/ft is attached to the collar and to the shaft and is undeformed when the collar is at A...

Homework Statement Express the number in the form a/b Homework Equations -2^{4} + 3^{-1} The Attempt at a Solution 16+(-3) = 13 Why is this not the correct answer?

[b]1. E=hf "find the energy level of light with a frequency of 4.3 x 10 so the 14th jules [b]2. E=hf [b]3. Have no clue, tried multiplying Plancks constant by frequency but idk if its right

Homework Statement I'm having a lot of trouble with this question. I don't even know where to begin. span{X1, X2, ... ,Xq}. a matrix A is m x n, and it is a zero matrix. Prove that AXp is NOT zero for some p.Homework Equations The Attempt at a Solution I'm guessing I need to show that Xi is...

Homework Statement http://img195.imageshack.us/img195/3056/mosfetj.jpg An n-channel enhancement MOSFET for which Vt = 2 V and K = 100 uA/V2 is operated from a 9 V supply using a drain resistor RD of 60kohms and the feedback bias scheme depicted. What drain current results? What is VD What...