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  1. J

    Engineering Basic Circuit - KVL

    Homework Statement Find the value of Vk http://oi54.tinypic.com/2s6x005.jpg Homework Equations The Attempt at a Solution Assuming dependent Vk = 12i -60 + 4i + 12i + 12i = 0 -60 + 28i = 0 i = 2.14 Vk = 12 * 2.14 = 25 .68 ? Answer is 18. Can someone tell me where I am going wrong ?
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    Engineering Badic Circuit - Nodal Analysis

    Basic Circuit - Nodal Analysis Homework Statement I am trying to find ix and iy. Here is the figure http://tinypic.com/view.php?pic=x2mr93&s=7 The Attempt at a Solution Node 1 -3 + V1/0.2 + (V1-V2/0.5) = 0 -.06 + 0.1V1 +0.2V1 - 0.2V2 =0 -.06 + 0.3V1 -0.2V2 = 0...
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    Engineering Basic circuit - power supplied

    Homework Statement In the Figure below if V 1=10 V and i x= -2 A, what is the power supplied by the dependent current source? Homework Equations The Attempt at a Solution The answer is -60. But I am getting 60. whenever It's power supplied doesn't it mean the current is...
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    Engineering Circuits-Mesh Analysis

    Homework Statement About this circuit: http://oi54.tinypic.com/eqwktd.jpg If I were to find ix. Would I be using supermesh? Homework Equations The Attempt at a Solution
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    Java Java-Bit Binary Number

    Question: Write a program that reads a four-bit binary number from the keyboard as a string and then converts it into decimal. For example if the input is 1100 the output should be 12. Attempt: import java.util.Scanner; public class run { private static final String number = null...
  6. J

    Java Java- reverse sentence

    We are asked to reverse a sentence , example: I am going. ==> .going am I Attempt: import java.util.Scanner; public class Assign2 { public static void main (String [] args) { String line= new StringBuffer().reverse().toString(); String line2 = new...
  7. J

    Java Java - using String Method

    Write a program that reads four-digit integer as a string , such as 1998 and then displays it, one digit per line, like so: 1 9 9 8 Attempt: Scanner keyboard2 = new Scanner (System.in); String integer2= "Input a 4 digit number:"; System.out.println(integer2); How do I make it read...
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    Physics- Pressure Problem , help

    Two containers contain the same gas at different temperatures and pressures, as indicated in the figure. The small container has a volume of 1 L, and the large container has a volume of 2 L. The two containers are then connected to each other using a thin tube, and the pressure and temperature...
  9. J

    Newton's law of gravity problem

    Homework Statement After a spacewalk, a 7-kg tool is left 54 m from the center of gravity of a 21-metric ton space station, orbiting along with it. How much closer to the space station will the tool drift in two hours due to the gravitational attraction of the space station? Homework...
  10. J

    Alternating Series Test

    Homework Statement summation --> (-1)^n+1 (2/3)^n (I don't know how to do the symbol for sum) The Attempt at a Solution I) lim n-->∞ (2/3)^n = limit does not exist ? It diverges ? P.S I am not sure if this is true. Any explanation will be a great help. Thanks.
  11. J

    Physics- center of mass problem ?

    Homework Statement The coordinates of the center of mass for the extended object shown in the figure are (L/4, −L/5). What are the coordinates of m1? (Assume m1 = 4 kg, m2 = 2 kg, and m3 = 3 kg. Use any variable or symbol stated above as necessary.) Here is the diagram ...
  12. J

    Physics - elastic problem

    Homework Statement Two balls of equal mass collide and stick together as shown in the figure. The initial velocity of ball B is twice that of ball A. (Take θ = 56°.) (a) Calculate the angle above the horizontal of the motion of mass A + B after the collision. (b) What is the ratio of the...
  13. J

    Physics conversion problem ?

    The electron-volt, eV, is a unit of energy (1 eV = 1.602 10^-19 J, 1 MeV = 1.602 x 10^-13 J). Since the unit of momentum is an energy unit divided by a velocity unit, nuclear physicists usually specify momenta of nuclei in units of MeV/c, where c is the speed of light (c = 2.998 108 m/s). In the...
  14. J

    Physics- mechanical energy

    Homework Statement A horizontal slingshot consists of two light, identical springs (with spring constants of 74 N/m) and a light cup that holds a 1-kg stone. Each spring has an equilibrium length l0 = 49 cm. When the springs are in equilibrium, they line up vertically. Suppose that the cup...
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    Nodal Analysis

    Homework Statement Find V1 and i1 using nodal analysis The Attempt at a Solution I know i1 is 0 because of a circuit break. But, I am not able to figure out how many nodes there are in this circuit? I thought there are four nodes connected to the reference point but the book...
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    Physics- Energy problem?

    Homework Statement Two baseballs are thrown off the top of a building that is 7.32 m high. Both are thrown with initial speed of 58.7 mph. Ball 1 is thrown horizontally, and ball 2 is thrown straight down. What is the difference in the speeds of the two balls when they touch the ground...
  17. J

    One / Two Dimensional Motion

    [b]3. The Attempt at a Solution [/b I tried to use the X= Vixt + 1/2axt^2 => 0= 1/2axt^2+ Vixt + X To find the time since there isn't a horizontal distance given. Then I realized the initial velocity for x and y direction can't be the same , but I don't have the angle. Do i have to find...
  18. J

    Magnitude of average velocity and average speed

    Homework Statement An electron moves in the positive x-direction a distance of 2.44 m in 3.10 *10-8 s, bounces off a moving proton, and then moves in the opposite direction a distance of 1.68 m in 3.53*10-8 s. The Attempt at a Solution to find the average velocity I used the distance...
  19. J

    Physics-magnitude/ displacement?

    Homework Statement A truck travels 3.45 km north and then makes a 90° left turn and drives another 4.10 km. The whole trip takes 4.50 min. 1)With respect to a two-dimensional coordinate system on the surface of Earth such that the y-axis points north, what is the net displacement vector of the...
  20. J

    Physics- velocity/ distance problem?

    Homework Statement An object starts from rest and has an acceleration given by a = Bt^2 − 1/2Ct, where B = 4.5 m/s^4 and C = −2.2 m/s^3 (1) What is the object's velocity after 7.5 s? (Indicate the direction with the sign of your answer.) (2) How far has the object moved after t = 7.5...
  21. J

    Physics- position

    Homework Statement The position of a particle moving along the x-axis is given by x = 4.7t2 − 3.2t3,where x is in meters and t is in seconds. What is the position of the particle when it achieves its maximum speed in the positive x-direction?
  22. J

    Engineering Circuit- Solving for Req

    Homework Statement Solve for Req The Attempt at a Solution The resistors in the middle can be added to total of 5 ohms. So then then 5v +5ohms = 10 ohms Then they are all in series 1.5+10+ 1.5= 12.5? What I don't understand is what do i do with Rx? or 12.5 is Req? Here is...
  23. J

    Engineering Circuits - Power absorbed / supplied

    Homework Statement I need to solve the circuit. I have trouble comprehending absorbed/supplied power concept. The Attempt at a Solution So, if power is being supplied by Vx then the current is passing out of the negative terminal towards the dependent source 4x and the element A? Vx *...
  24. J

    Free fall?

    Homework Statement The question asks me to explain why the graphs should be a straight line? We had to make a Distance vs Time^2 graphs. The Attempt at a Solution On a position x time graph If the ball is falling only way it can be a straight line if the velocity is constant , right...
  25. J

    Distance v.s Time graph shape?

    Homework Statement What would be the shape of Distance vs Time Graph when a ball is falling? Please explain. Thanks you The Attempt at a Solution I think it will be a curve since the acceleration is constant (9.8 m/s^2) . the slope under the curve will be velocity which will...
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    Calc- prove sinh(x) and cosh(x) identities?

    Homework Statement Prove cosh(2x)= cosh^2(x) + sinh^2(x) Homework Equations sinh(x) ≡ [ e^(x) - e^(-x) ] / 2 cosh(x) ≡ [ e^(x) + e^(-x) ] / 2 The Attempt at a Solution = { [ e^(x) + e^(-x) ] / 2 }² + { [ e^(x) - e^(-x) ] / 2 }² = [ e^(x) + e^(-x) ]² / 2² + [...
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    Calc- Force Problem

    Homework Statement A Force of 7 pounds is required to stretch a 40 inch spring to a length of 43 inches. How much work will be done in stretching the spring an additional 6 inches from its already extended length of 43 inches? The Attempt at a Solution I know how to integrate , just...
  28. J

    Engineering Circuit Analysis problem ?

    The power supplied by a certain battery is constant 6 W over the first 5 mins, zero for the following two minutes, a value that increases linearly from zero to 20 W during the next 10 minutes, and a power that linearly decreases 20 W to zero in the following 7 minutes. What is the total energy...
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