Search results

  1. R

    Substitution, algebra.

    Homework Statement 5a = 5 - b 5a = 3 - b Homework Equations The Attempt at a Solution I got the solution set to be 1/2, 5/2 i used substitution for substituting a into b of the second equation, just like they were x's and y's just used a's and b's there is no difference...
  2. R

    Finding slope intercept form.

    Homework Statement find the slope-intercept form for the line satisfying the following conditions x intercept 2, y intercept 2/3 Please let me know if I solved this correctly. Thankyou. Homework Equations The Attempt at a Solution 2, 0 0,2/3 (2/3 -0) / (0 - 2) 2/3 / -2/1 2/3 * -1/2...
  3. R

    Solving this equality. Then simple plot.

    Homework Statement 7/2x >= -1/4 then put it on a number plot. Homework Equations The Attempt at a Solution 7x/7 >= -2/4 = -1/2 -1/2 *7/1 = -7/2 x>= -7/2 and I'm not sure if I'm even correct for that answer, and I have to put it on a number plot.
  4. R

    Finding dimensions of a rectangle.

    Homework Statement the perimeter of a rectangle is 24 ft. the length is 4 ft longer than the width find the dimensions width x length x+4 however, I should be doing it like this: a first equation should start like: 2x+2y=? and the second should start like x=y+? so whats the...
  5. R

    Adding variables with same exponents

    Homework Statement solve. .2y^3 + .6y^3 - .5y^3 I believe the answer to be .3y^3 Homework Equations The Attempt at a Solution i got the answer to be .8y^3 - .5y^3 = .3y^3 I think this is correct, I'm not sure, please let me know if I finished this correctly.
  6. R

    Area of this triangle

    Homework Statement area of triangle with a base of: 2 & 3/4 and a height of 4/9 Homework Equations 1/2 * (b*h) The Attempt at a Solution i used: 1/2*(11/4 * 4/9) = 44/72 = 22/36 = 11/18
  7. R

    Using symbols to rewrite the problem and then solve it.

    Homework Statement use symbols to write and evaluate this problem four squared divided by two to the fourth power Homework Equations The Attempt at a Solution 4^2 / 2^4 the answer I get is 1
  8. R

    Find slope of line, two points on the line are included

    Homework Statement find the slope of this line it contains these points: (-16, -1) , (-17, -7) Homework Equations y = mx + b The Attempt at a Solution i got y = 3/8x - .625 is that correct? my work i use -7 +1 / -17 + 1 ==-6/16 ==6/16 = 3/8 then i used -7 =...
  9. R

    Electric field at origin, zero or nonzero?

    Homework Statement Point charges +q and -q are placed at +50 cm and -50 cm on the x-axis, respectively. Is the electric field at the origin (halfway between the charges) zero or nonzero? If nonzero, which direction does it point? Homework Equations The Attempt at a Solution If...
  10. R

    Using Kirchoff's junction rule for current from a battery.

    Homework Statement Use Kirchhoff's junction rule to calculate the current supplied by the battery. Homework Equations attached a pic. The Attempt at a Solution Where do we start?
  11. R

    Current through resistor, with heat. What happens to the current?

    Homework Statement Suppose a current of 1 A is flowing through a resistor. If this makes the resistor heat up, will the current through the resistor increase, decrease, or remain constant? Assume the voltage applied to the resistor is constant. Homework Equations The Attempt at a...
  12. R

    Electron moving from point A to B. electron potential higher?

    Homework Statement An electron , influenced only by electric fields and forces, moves from A to B. When it reaches B, its speed is higher than it was at A. Is the electric potential higher at A or at B? Homework Equations The Attempt at a Solution So as the electron gets closer...
  13. R

    Point charges, midpoint zero or non zero?

    Homework Statement Point charges +q and -q are placed at +50 cm and -50 cm on the x-axis, respectively. Is the electric field at the origin (halfway between the charges) zero or nonzero? If nonzero, which direction does it point? Homework Equations The Attempt at a Solution Well...
  14. R

    Image created by concave mirror, sight from a distance.

    Homework Statement A science museum has created a huge concave mirror with a focal length of 5 m, and mounted it so that it covers the entire wall at one end of a long hallway. If you stand on a center line painted down the middle of the hallway, you're on the mirror's principal axis. You...
  15. R

    Moving particles electrons and protons, using magnet to deflect fictional idea.

    Homework Statement An alien civilization has crossed the galaxy to invade the Earth and enslave humanity, again. Their attacks have been successful so far because their assault troops are equipped with handheld weapons that project beams of charged particles (protons & electrons) at very...
  16. R

    Why test charge slows down in terms of electric potential and EPE.

    Homework Statement a large positive charge +Q fixed at some location in otherwise empty space, far from all other charges. A positive test charge of smaller magnitude +q is launched directly towards the fixed charge. Of course, as the test charge gets closer, the repulsive force exerted on...
  17. R

    Calculating current from diagram.

    Homework Statement from the diagram i drew I want to calculate the current in the battery for the circuit, can someone help me with this. Want to use symbols too. R1 and R2 are in series, they are in parallel with R3, and R4 is in series with R1, R2, and R3. The diagram is attached...
  18. R

    Electric field and electric charge, whats going on in the diagram.

    Homework Statement This picture shows two points charges, q1 = +5 nC, and q2 (unknown), fixed in place on the x axis. At the location marked P, the net electric field due to both charges is zero: EP = 0 N/C. Based on the information shown in the picture, what can you conclude about the...
  19. R

    AI search strategies using discrete mathematics

    Homework Statement The question is to provide a new composite heuristic h3 that is admissible and dominates h1 and h2. Then show the cost of each of the states through H according to h3. Homework Equations States: A B C D E F G H h1: 10,12,12,6,7,7,2,10 h2: 8, 9, 14,4,9,7,1,9...
  20. R

    Infinite sequence w/ factorials

    Hi, I was just looking at this problem with sequences and I was having a question about factorials. I understand that the factorials need to get smaller. I was just wondering what is the (3)(2)(1) in the problem symbolizing? Just that it will eventually reach the end? and what numbers...
  21. R

    2 focal points, find image distance.

    Homework Statement An object is placed in front of a converging lens in such a position that the lens (f = 15.0 cm) creates a real image located 21.0 cm from the lens. Then, with the object remaining in place, the lens is replaced with another converging lens (f = 16.0 cm). A new, real image...
  22. R

    Boat light distance when it strikes bottom.

    Homework Statement A spotlight on a boat is y = 2.5 m above the water, and the light strikes the water at a point that is x = 9.5 m horizontally displaced from the spotlight (see the drawing). The depth of the water is 4.0 m. Determine the distance d, which locates the point where the light...
  23. R

    Angle refraction from a point on glass.

    Homework Statement The drawing shows a rectangular block of glass (n = 1.52) surrounded by liquid carbon disulfide (n = 1.63). A ray of light is incident on the glass at point A with a = 36.0° angle of incidence. At what angle of refraction does the ray leave the glass at point B? Please...
  24. R

    Archived Current of Coil, and Emf of Coil.

    Homework Statement A magnetic field is perpendicular to the plane of a single-turn circular coil. The magnitude of the field is changing, so that an emf of 0.91 V and a current of 3.2 A are induced in the coil. The wire is the re-formed into a single-turn square coil, which is used in the...
  25. R

    MRI emf rating problem.

    Homework Statement Magnetic resonance imaging (MRI) is a medical technique for producing "pictures" of the interior of the body. The patient is placed within a strong magnetic field. One safety concern is what would happen to the positively and negatively charged particles in the body fluids...
  26. R

    Change in magnetic flux

    Homework Statement A loop of a wire has the shape shown in the drawing. The top part of the wire is bent into a semicircle of radius r = 0.24 m. The normal to the plane of the loop is parallel to a constant magnetic field ( = 0°) of magnitude 0.75 T. What is the change in the magnetic...
  27. R

    Determine curve

    Homework Statement Determine whether the curve x = 3t^2, y = e^2t+1 is concave up or concave down at the point (3, e^3) thanks for any help with this one. Homework Equations The Attempt at a Solution know i need to take the double derivative. Also that would be 6 and...
  28. R

    Curve problem

    Homework Statement Prove that the curve x = t cos(t), y = (pi/2 - t) sin(t) has a self-intersection at the point (0,0) Homework Equations The Attempt at a Solution not sure where to start with this one. Please help.
  29. R

    Evaluate the integral as infinit series.

    Homework Statement Evaluate the indefinite integral as an infinite series. here is the problem: http://aycu28.webshots.com/image/38987/2005883203189533192_rs.jpg Homework Equations The Attempt at a Solution not sure what test to use. My first guess would be to use the integral...
  30. R

    Taylor Series

    Homework Statement Find the Taylor series for f(x) = sin x centered at a = pi / 2 Homework Equations The Attempt at a Solution Taylor series is a new series for me. I believe the first step is to start taking the derivative of the Taylor series. f(x) = sinx f'(x) =...
Top