What is Concave: Definition and 200 Discussions

Homework Statement A concave spherical mirror has a radius of curvature of magnitude 27.1 cm. Determine the object position for which the resulting image is inverted and larger than the object by a factor of 4.00. Homework Equations Mirror equation in terms of focal length: 1/p + 1/q =...

Where is the best location for a light bulb filament to be placed in a spotlight, when using a concave mirror? It makes the most sense to put it at the focal point of the mirror if you want parallel light beams but are you supposed to have parallel light beams when you use a spotlight? Or do...

Classic paraboloidal mirror. Incoming flat wavefront of known wavelength (500 nm, green light), propagating parallel to the major axis of the mirror. The wave hits the mirror and is being sent back towards focus. At the focal plane, there's a flat CCD or some other light detector. Upon hitting...

I need a concave function in 2 variables X and Y for some modelling I'm doing. For 0<x<1 and 0<y<1, the function needs to satisfy the following: f(x,y) < 0 for x<0.5 and/or y<0.5 f(x,y) = 0 for x=0.5 and y=0.5 f(x,y) > 0 for x>0.5 and y>0.5 MUST be concave.. i.e. second order partials...

A certain 0.86 cm lens is used in a peephole for hotel room doors for safety reasons. The tenant sees the maid in the peephole but she is reduced in size by a factor 0.01. A. What type of lens must be used? B. Where is the image of the maid located? C. What is the power of this lens...

Homework Statement A circular concave lens of radius 2 units, has two refracting surfaces described by z=1/2(x2+y2+1) and z=-1/2(x2+y2) What is the volume of the glass? Homework Equations Over a region R: V=\int\int\int dA The Attempt at a Solution I have no idea how to start...

Why is f(x)=(x-3)^2/(x-6) not concave up for x>6? It looks like it is from the graph.

how can we say that the image formed by a concave mirror is always real if object is virtual? please help

Homework Statement Let f:[0,2]\rightarrow[0,\infty) be continuous and non negative. Assume thaqt for any x,y\in[0,2] and 0<\lambda<1 f(\lambda x+(1-\lambda)y)\geq\lambda f(x)+(1-\lambda)f(y) . Given that f(1)=1 prove \int_{0}^{2}f(x)dx\geq1 The Attempt at a Solution I've...

Homework Statement In my textbook, the author briefly makes a statement that affine functions are both concave and convex, how is that true? and how can it be proven? Homework Equations The Attempt at a Solution

Homework Statement "a concave mirror is placed horizontally on the ground with a focal length of 1 meter, a boy sitting on a tree above the mirror drops a 7cm diameter styrofoam ball right over the mirror 3 meters high, determine when the image will be the same size of the ball" Homework...

Homework Statement A dentist uses a curved mirror to view teeth on the upper side of the mouth. Suppose she wants an erect image with a magnification of 2.00 when the mirror is 1.25 cm from a tooth. (Treat this problem as though the object and image lie along a straight line.) What kind of...

For the equation: contact stress = {(1 / (pi[((1-v1^2)/E1)) + ((1-v2^2)/E2))) ^ 0.5} * {((Fn/b) * (Sum (1/pi)))^0.5} Where Sum (1/pi) = [(1/p1) - (1/p2)] for concave shapes in contact with convex shapes Sum (1/pi) approaches 0 as the two radii get closer, however when the two radii...

if one was able to make a perfect concave mirror with half a cube shape perfect mirror in front of it ( so thermally isolated from outside with a perfect vacuum inside it) And a black body almost covering the front of the Concave mirror that is red hot and another much smaller black body in the...

Let f(x)=x^6ln(x) . Find (a) the intervals on which f is increasing, (b) the intervals on which f is decreasing, (c) the open intervals on which f is concave up, (d) the open intervals on which f is concave down, and (e) the x-coordinates of all inflection points. (a) f is increasing on the...

Homework Statement Homework Equations 1/f=1/i + 1/p m=-i/p Where m is magnification, i is image distance, p is object distance, and f is the focal length. The Attempt at a Solution 1/f = 1/1.5f + 1/i i=3f I have also attempted to draw a ray diagram to use the image of...

Hi I have read several papers and found that for both sound beam /light beam , the sound pressure obtained is higher when a concave /curved reflector is used in place of a flat reflector. Can anyone tell me why? Is it related to soem consideration of energy loss from the wave? If...

Homework Statement A concave mirror of focal length 20cm forms an image which is three times the height of the object. Find the distance of the object from the mirror if: 1: The image is real 2: The image is virtual...

Homework Statement An object 23.0 mm high is 31.0 cm away from a concave spherical mirror with a radius of curvature of 54.0 cm. What is the absolute size of the image? Homework Equations Maybe these are relevant Mirror equation in terms of focal length...

Problem: A small postage stamp is placed in front of a concave mirror (radius=R), such that the image distance equals the object distance. (a) in terms of R, what is the object distance (b) what is the magnification of the mirror (c) state whether the image is upright or inverted relative to...

Homework Statement A question I had in an exam today, just wanted to see whether it was right: A ball is rolling down the inside of a concave surface. The radius of the ball and the curvature of the surface is such that there is no slide. Is work done by a) the friction force b) the Normal...

It's been a while since my last calc course and I'm not sure if I even encountered how to do this but is there a way to derive a function of a concave downward sloping curve given two or more points and their respective slopes? I'm obviously aware how the curve looks but I would like to know...

Homework Statement Sunlight falls on a concave mirror and forms an image 3.0 cm from the mirror. If an object 24 mm high is placed 12.0 cm from the mirror, where will its image be formed? a. Use a ray diagram b. Use the lens/ mirror equation c. How high is the image? Homework Equations...

1. I need to find where the graph of f is CU or CD given the graph of f ' . 2. So far I have found that F inc. on (2,4) and (6,9). F has a local max at 4. F has a local min at 2 and 6.

Homework Statement 1)A concave mirror produces a virtual image that is three times as tall as the object. a) If the object is 21 {\rm cm} in front of the mirror, what is the image distance? b) What is the focal length of this mirror? Homework Equations hi/ho di/do 1/f= 1/do...

Homework Statement A person accidentally bit his tongue and wants to examine the bite by using a concave mirror. The mirror is placed 10 cm from the bite with the result that a virtual image of the bite appears 4 times actual size. Find the parameters s (distance from object to mirror), s'...

When you look at a spoon, like at a mirror, the image of yourself appears to be on the other side of the mirror/spoon, where light does not go! So the image must be virtual! So tell me, since a concave mirror must produce a real inverted image when you are far from the focal point...

Homework Statement I have a concave lens where f < do < R. I have to provide a ray tracing diagram. The Attempt at a Solution I drew the focal ray through the focus and parallel to the principal axis. I drew the principal ray parallel to the principal axis then through the focus. I...

I want to know when a vehicle travels at a constant velocity along a convex and concave bridges, in what bridge the normal reaction of the vehicle is higher... I think it is on cancave bridge... am I right? because I got it by equations...

Homework Statement For each thin lens shown in the figure , calculate the location of the image of an object that is 18.5 {\rm cm} to the left of the lens. The lens material has a refractive index of 1.50, and the radii of curvature shown are only the magnitudes...

Homework Statement If the focal length of the concave lens is -7.50 cm, at what distance d_o from the lens should an object be placed so that its image is formed 3.70 cm from the lens? What is the magnification m produced by the concave lens described in above? Where should the object be...

1. Find the length of the curvature of a concave mirror of 20cm that comply with paraxial approximation for all incident rays 2.conventional geometry formula , sinθ≈θ or tanθ≈θ for paraxial rays 3. I had try drafting out the diagram , labeling all the unknown angle with symbol and...

I've two questions here:- 1) Sound reflects it is said using laws of reflection of light.So,it means we hear max. sound when angle of incidence is equal to angle of reflection,right?& if not equal then what do we hear or not? I guess we hear lesser than max.sound when the angles are not equal...

Homework Statement We did an experiment with a concave mirror. Concave mirror was placed on optics bench and a candle was placed at designated spots. A screen was used to see where the image was projected. When the object was placed between the focal point, image was not produced on the...

Hi, We're offered shaving mirrors by suppliers and sometimes their claims to the magnification are doubtful. I don't wish to upset any customers by giving incorrect information. So is there a practical way in which I can test the magnification myself? i.e. measuring the distance of the...

Hello everyone, Quick questions What happens to the light ray that passes through the mid point of the lens(dotted line). Does it go straight or diverge? Is moon concave? If the light passes right through the midpoint travel straight wouldn't the umbra have some light in the...

Where do you put an object in front of a concave mirror of focal length 10 cm to produce an image that is inverted and 2.5 times greater than the object? I have no idea how to solve this.. help..

Homework Statement A concave mirror of focal length 10cm in air is put into a beaker containing a liquid up to 7.5cm. Refractive index of the liquid is 1.2. What is the focal length of the mirror inside the beaker? The Attempt at a Solution I tried proportion method: Depth...

Homework Statement the question is attached The Attempt at a Solution ok so a and b i can do but c), i donts know whether my answer is right and I am a little confused about the conceptual idea... so first thing i did was found the radius of curvature using the lens maker equ...

1. The image of the moon is formed by a concave mirror whose radius of curvature is 4.20 m at a time when the moon's distance is 3.8 x 10^5 km. What is the diameter of the image of the moon if the diameter of the moon is 3480 km? 2. 1/f = 1/do + 1/di M = hi/ho = - di/do 3...

Homework Statement A concave mirror with a focal length of 34.4 cm produces an image whose distance from the mirror is one-third the object distance. Calculate the object distance. Homework Equations (1/f)=(1/do) + (1/di) The Attempt at a Solution I know that i have to use the...

Homework Statement A physics student wants toobtain a real and virtual image that each is 3 times as large as the original object she has a concave mirror with a 0.50 m radius of curvature. what object distance will she require to obtain the real image? Homework Equations 1/do + 1/di =...

17. For what value of x is the graph of y = 2 / (4 - x) concave downwards? I found the first derivative = 2/(4-x)^2 And then the second 4/(4-x)^3 But I think I might have messed up somewhere in there

concave mirror! Homework Statement The real image produced by a concave mirror is found to be 0.756 times the size of the object. If the distance from the mirror to the screen on which the image appears is 0.764 m , what is the focal length of the mirror? Homework Equations (a) 1...

Homework Statement A concave mirror has a focal length of 27.2 cm. The distance between an object and its image is 50.2 cm. Find (a) the object and (b) the image distance assuming that the object lies beyond the center of curvature. Homework Equations f=1/2 R 1/object distance + 1/image...

I know that when the focal point is in the inside of a concave mirror. The focal point is greater than zero, and the radius is greater than zero and the lateral magnification is greater than zero. So if the focal point is on the outside of this concave mirror. Would the focal point be...

I am looking for a "good" way to triangulate a closed concave shape of vertices and edges. "good" is quite a vague term, but the basic principles I'm interested in are: 1) Minimize "sliver" triangles that are very thin and contain really small angles. 2) Must be reasonable to compute...

hello, I found a concave mirror telescope in my town I think that it is very good for making Newton telescope Estimated length of 20 cm I will make a telescope , but I have a problem , I do not know the place of the focus and the place of secondery mirror; after focus or before...

Homework Statement A concave mirror with a radius of curvature of 1.4 m is illuminated by a candle located on the symmetry axis 3.4 m from the mirror. Where is the image of the candle? Answer in units of m. Homework Equations The Attempt at a Solution I tried plugging in the...

A concave mirror creates an image on the screen 2x larger than the object. BOTH objects and screen are subsequently moved in order to create an image on the screen 3x larger than the object. If the screen is moved 0.75 m in this process, how far is the object also moved? --- Magnification, M =...