Is this derivation RIGHT(physics)? Answered

Hi to whoever is reading this.Yesterday me and my friend derived an expression relating mass of a photon and its frequency .Can anyone tell me if its right?Ps I'm only 15 years old so i may not be right . Here is the link for it: the folder name isPMF.docx and anyone can view it https://drive.google.com/file/d/0B391sIgwIxyvZ196MmtMTFJFa1k/edit?usp=sharing also thank you in advance.

Asked by Strontium 4 years ago


Which servo should i choose?

I am  planning to make a servo automated nerf gun but i am not sure what type of servo to choose.Is it the 9g series or the bigger ones. I really don't want to choose the wrong one,.The nerf gun is a nerf barricade rv-10 and i'm not sure how much force is required to pull it's trigger.It would be really great if someone could help me out.

Asked by Strontium 4 years ago


Things to do with a broken flash drive

Hello there. I just broke my 16GB Strontium Pollex drive and I'm left with nothing but the circuit board (Pics below). It doesn't fit into the USB port (too small, push up=on, remove support=off) smugly, and well, this is my only 4GB+ flash drive (I have another broken 1GB one, but at least it doesn't wobble around in the port). What do I do with this to make it usable again?

Posted by NSDCars5 5 years ago


Comparator Inputs ?

On the two inputs of a standard comparator op amp (say for example  LM741)  they usually  connect resistors from both the positive and negative voltage rails .Why do they do this and how does this work . This has been on my mind for a really long time . Could someone give me a really detailed explanation maybe with images if possible , cause this would be really helpful in the building of my next project .Most of the tutorial videos out there , i don't understand either. Thank you in advance  

Asked by Strontium 4 years ago


Problems with power supplies.

I made a small circuit board which is a proximity sensor that turns on or off a small philips genie light(its a small white tubelight like light ).i tried powering it up with a 9v battery and it works fine and the relay on the circuit board switches the ac220v load and the light goes on ,however when i try powering it up with a 10vdc adapter the relay on the circuit board keeps clicking(here i have not used the ac load to switch the tubelight,i was just experimenting and came upon the problem) .what should i do .pls help me.  

Asked by Strontium 5 years ago


Problems with logic(NAND) gates? Answered

I MADE a circuit that basically detects when an IR beam  is cut using a LM741 opamp .AS shown in the schematic i've connected the output of the opamp to the  two transistors (which is a nand gate) ,so when the beam is cut the output of the transistors should be high but instead the led at the collecter of the transistor glows only brighter. should i use a nand gate in a DIP package ?also when i individually measured the output of the opamp it showed that there was constantly 1.5 v coming out i tried measuring it with both opposite polarity leads of the multimeter  ,still  it showed a 1.5 v output,why does this  happen?PLS help.i need it fast.

Asked by Strontium 5 years ago


Why do i solve the sum in this way (mathematics)?

The sum is as given below: "There are two cars A and B.They start from the same point at the same time and travel in a circular path .Car A can complete one round in 18 minutes whereas car B can complete the round in 16 minutes. After how much time will they meet?"   my maths teacher told me to take the LCM(least common multiple) of their respective completion times of a round. Can anybody please explain to me as to why i should take the LCM. Also i would be greatful  if you could explain it simply.Cheerio.

Asked by Strontium 4 years ago


About the components of light ?

I just learnt that light consists of electric and magnetic fields oscillating at right angles to each other . Now my question is that why can't the electric and magnetic components of light interact with matter. For example why does not the magnetic component in light interact with a external magnetic field and bend toward or away from it. Also how do we tell the direction of magnetic and electric fields in light . I know that this question might seem really dumb , but i seem to have a great difficulty in understanding light and would be really satisfied if some could give or direct me to a detailed explanation. Thanks in advance ..

Asked by Strontium 3 years ago


GID Vials, Tritium, TRASERS, Powders and Chemicals GLOW IN THE DARK!

TRITIUM! So I get a lot of questions from my post and instructables. Tritium Vials are Radioactive Hydrogen H3, also known as hydrogen-3 is a radioactive isotope of hydrogen. It is contained in small glass vials coated in colored phosphor then encased in glass or sealed plastics. These are commonly seen in Gun Sights, Watches (TRASERS) and some Emergency Exit Signs. http://en.wikipedia.org/wiki/Tritium_illumination Small amounts are legal and for approved uses. Read the NRC guides Typically the Trit vials are small, expensive and dim. The latest GID (Glow in the Dark) Chemsticks, LED's and GID Powders or paints seems much more effective and usable. * Cyalume, as used in a lightsticks, emits light by chemiluminescence of a fluorescent dye (also called fluorescor) activated by cyalume reacting with hydrogen peroxide in the presence of a catalyst, such as sodium salicylate. It is the most efficient chemiluminescent reaction known. up to 15% quantum efficiency. http://en.wikipedia.org/wiki/Chemiluminescence New LED low power requirements and high Lumen or light output have provided many solutions that are low cost, high power and longer lasting. GID Paint or Powders are "charged" with light or daylight sources as with your traditional kids toys or stickers. New products are brighter, glow longer and are now waterproof, have many colors and applications. http://www.4physics.com/catalog/GIDinfo.php Also this is occasionally confused with the chemical illumination. However these paints powders and materials use common phosphorescent materials include zinc sulfide and strontium aluminate. Use of zinc sulfide for safety related products dates back to the 1930s. However, the development of strontium oxide aluminate, with a luminance approximately 10 times greater than zinc sulfide, has relegated most zinc sulfide based products to the novelty category. Strontium oxide aluminate based pigments are now used in exit signs, pathway marking, and other safety related signage. http://en.wikipedia.org/wiki/Phosphorescence Hope this helps! 01/2011 - Update Source for Materials http://www.darkniteglow.com/glow-shop/ ERCK www.Candlepowerforums.com Additional Tritium Resources * U.S. NRC: http://www.nrc.gov/reactors/operating/ops-experience/grndwtr-contam-tritium.html * U.S. EPA: http://www.epa.gov/radiation/radionuclides/tritium.htm * U.S. DOE (Argonne National Lab): http://www.ead.anl.gov/pub/doc/tritium.pdf * California EPA: http://www.oehha.ca.gov/water/phg/allphgs.html * University of Idaho: http://www.physics.isu.edu/radinf/tritium.htm

Posted by erckgillis 7 years ago


Inexpensive glow in the dark writing

Desired effect:Paint a Wall or furniture write on it or draw then it fades 1 less than a minute then you can draw againMaterials:-1 UV LED (low power any chinese anti fake bill keychain will do)-Any surface -Common glow in the dark paint or powder Low grade Zinc sulfide glow in the dark paint (or strontium oxide aluminate glow in the dark paint ) We have to find a way to lower the performance of the compounds so that they glow for 10-40 seconds maximum instead of hours.WHAT IS NEEDED: A CHEMICAL DETERRENT TO LOWER THE PERFORMANCE OF THE PAINT: HELP IS NEEDED I DO NOT KNOW WHAT COMPOUND TO USE. (IT MUST DECREASE THE PERFORMANCE BUT NOT THE BRIGHTNESS in dim light)Help complete this instructable, (pretty please)

Posted by dejabox 10 years ago


Which Servo Should I Choose For My Nerf Gun?

I wanted to build a servo automated nerf gun ,however i am not sure what type of servo i should choose and how much torque i will require.The gun i want to trigger is a semi automatic nerf barricade rv-10 .Should i buy the small 9g hobby servos' or will my need be satisfied y the larger ones which provide torque.I am not using anything to amplify the pull of the trigger by the servo and i am connecting the servo horn directly to the trigger using a small metallic wire like piece .Please help me chose a servo. 

Asked by Strontium 4 years ago


Problem with the HEF4008BP IC chip ??

I just bought a HEF4008BP 4 bit binary adder ic. I connected pin 16 to V+ and pin 8 and 9(Carry in pin ) to ground  and then set up a 8 way DIL switch with 10k and 1k pull down resistors to gnd and the switch  to the inputs of the adder.Then i connected the outputs of the adder to the positive of a 3mm led each separately  .The dil switches are all of but still all the led's light up once i connect the 9v battery . The chip can run off 5v-15v . Also there is no sign, name or logo of a manufacturer on the ic .Is this a fake ic or might i have possibly blown it or have i done something wrong .Please help me.

Asked by Strontium 4 years ago


Write on anything: INexpensive glow in the dark writing

Inexpensive glow in the dark writing Desired effect:Paint a Wall or furniture write on it or draw then it fades 1 less than a minute then you can draw again Materials: -1 UV LED (low power any chinese anti fake bill keychain will do) -Any surface -Common glow in the dark paint or powder Low grade Zinc sulfide glow in the dark paint (or strontium oxide aluminate glow in the dark paint ) We have to find a way to lower the performance of the compounds so that they glow for 10-40 seconds maximum instead of hours. WHAT IS NEEDED: A CHEMICAL DETERRENT TO LOWER THE PERFORMANCE OF THE PAINT: HELP IS NEEDED I DO NOT KNOW WHAT COMPOUND TO USE. (IT MUST DECREASE THE PERFORMANCE BUT NOT THE BRIGHTNESS in dim light) Help complete this instructable, (pretty please)

Posted by dejabox 10 years ago


I've got a relay switching problem. Answered

I've got a relay problem.i made a proximity sensing tubelight that goes on/off when an object moves above it .i used 3 ic's :lm741,cd4017,and a 555 timer and i added a relay to the outputs of the cd4017 counter to the relay via a transistor to protect my ic's.however when i don't connect the 220v ac to the load of the relay it functions fine but when i connect 220v ac to the load ,the relay keeps clicking on and off.i have seen the voltage ratings for the relay .it is a 5v relay and can handle 250 v ac but it does not work properly.The whole circuitry is powered by a 9v battery.i am not sure whether it is a problem of not enough power or something else..i'm a electronics hobbyist and i need help .PLS ANSWER?.

Asked by Strontium 5 years ago


Inexpensive glow in the dark writing: WRITE ANYWHERE

Inexpensive glow in the dark writing Desired effect:Paint a Wall or furniture write on it or draw then it fades 1 less than a minute then you can draw again Materials: -1 UV LED (low power any chinese anti fake bill keychain will do) -Any surface -Common glow in the dark paint or powder Low grade Zinc sulfide glow in the dark paint (or strontium oxide aluminate glow in the dark paint ) We have to find a way to lower the performance of the compounds so that they glow for 10-40 seconds maximum instead of hours. WHAT IS NEEDED: A CHEMICAL DETERRENT TO LOWER THE PERFORMANCE OF THE PAINT: HELP IS NEEDED I DO NOT KNOW WHAT COMPOUND TO USE. (IT MUST DECREASE THE PERFORMANCE BUT NOT THE BRIGHTNESS in dim light) Help complete this instructable, (pretty please)

Posted by dejabox 10 years ago


Does my instructable stand a chance of winning? Answered

Well i recently entered  my instructable for the Pocket Sized Electronics  Contest and i just wanted to know a few details about the competition and whether my instructable stands a chance of winning my instructable: https://www.instructables.com/id/DIY-Pocket-Sized-Anti-Theft-Alarm-/ if you think its good  vote for me. my doubts about the competition -how do i find the  how many people have voted for me? -do your instructable have to be popular or have many views to win the competition? -if you win the competition do you have to pay money for claiming the prize or for shipping of the prize? i would like to receive constructive criticism from everybody about my projects as this is one of my first few instructables and please comment about my instructable  . Thank you

Asked by Strontium 4 years ago


DC Motor Problem?

Hi , to whoever is reading this .I wired 2  3v dc toy motors in series and I used about 4.5v as the power source. As I powered it up one motor spun fast and the other spun slower , so I thought the one running slower was defective an so I bought another motor and wired it in series with the  that was spinning fast and thought their speeds would be equalled, however the new one I bought started running faster and the old I one I had that spun faster began spinning slower than the new one. I tried the new one with the old one that had been spinning slower and arrived at the same result.. Could this be because I wired the motors in series ? I  Really need help s o please help me and thank you in advance and for taking the time the read this.

Asked by Strontium 4 years ago


Problems With My HXT HX5010 servo.

I recently bought a HXT  HX5010  twin bearing servo.First it did'nt work when i tried powering it off the arduino ,so i switched to a separate power supply and connected the gnd of the power supply to the gnd of the arduino and then it started behaving better.When i ran the "sweep" program on the arduino the servo started sweeping however i noticed that it did only around-about 160 degrees and not a full 180 degree sweep.Even when the servo tried to do a full 180 degree sweep,as it reached the far end(180 degrees) it would lock itself and not move and a low grinding sound would be emitted from the servo after it got locked.Does my servo have bad gears?,should i lubricate them?This is the first time i've ever used a servo ,so please help me out!

Asked by Strontium 4 years ago


Problems with my arduino mini shield

So i built an arduino mini shield for displaying numbers(i used the 4511 bcd to 7 segment decoder ic ) using only 4 pins excluding v+ and v-(power).It seemed to work well for while but later when i tried displaying 0001 ( 1 in binary) ,it suddenly stopped working or some all the segments got dimly lit . .Also if i plug it into the breadboard and connect some jumpers to the pins of the arduino(+5v and gnd) ,it seems to work fine,however when i plug it directly into the arduino,setting pin13 high and the gnd pin near it ,it does'nt work properly and all the segments glow dimly.The control pins for the digits are pin 12,11,10 and 9.also when i plug it into the breadboard and instead of connecting the pins with jumpers to +5v and gnd of the arduino,if i connect it to pin 13(HIGH) and the gnd near it it displays only 8, also can't i use pin 13 being HIGH as 5v' s? WHAT AM  I SUPPOSED TO DO?

Asked by Strontium 4 years ago


How should i write this program (arduino)?

Hi,To whoever is reading this.I've been working with arduino for a few days and I don't knoiw how to make a program where if you press on button the arduino receives an input on some pin as HIGH  and then it increases the position of the servo clockwise and when you press another button and the arduino receives HIGH on some other pin and makes the servo tern anticlockwise.I've been trying to nail it but i just can't get it .I even tried this program and it did'nt work .Can anyone HELP me?.Thanks in advance.  #include Servo myservo;  int pos = 0; int up=13; int down=12; int a=0; void setup() {   myservo.attach(9);    pinMode(up,INPUT);   pinMode(down,INPUT); } void loop() { if(up==HIGH)      {       a=1;      }   if(down==HIGH)      {       a=0;      }      for(a=1; pos = 0; pos     {                                     myservo.write(pos);                delay(15);                           }   for(a=0; pos = 180; pos>=0; pos-=1)         {                                    myservo.write(pos);                  delay(15);                   } }

Asked by Strontium 4 years ago


Problems with the 4511b IC chip??

SO i made a circuit which is a binary adder(using the 4008b) that adds numbers in binary and then passes on the result to a 4511 IC(its a BCD to 7 segment decoder),so basically it adds numbers in binary and displays them in decimal .It seemed to work fine for a while but then suddenly when i tried adding 0011 +0001(3+1) in binary ,it still displayed 0 and then i tried tapping the battery for a second or two and then suddenly the seven segment display shows 4 .The circuitry is all fine and right .but do i have to connect latch enable(pin 5) pin of the Ic?.Both the IC's run on a 9v battery and for the 4511 decoder IC i used 33k pull down resistor .Is my pull down resistor value for the 4511 IC too high ?The binary adder part seems to work very well,its the bcd to 7 segment decoder IC part that I'm very much concerned about.Is there too less power for both the chips to run on?I've not got a single idea at all .so, >PLS help me if you can.

Asked by Strontium 4 years ago


Chemicals people would want to make?

Basically I want to know what lab chemicals you want to make, if you know how to make any useful chemicals. please post, I am not responsible for and injury's, fatality's, or "bad things" of any sort that come from this thread, all things posted here are to assumed for informational purposes only.

Posted by mr.space 8 years ago


Simon Field's Science Toys

On my visit to Simon Field's farm, Simon showed my friends and me a great many awesome tricks and toys.  Of course, Simon does run Scitoys.com so this isn't surprising!  First we saw his workshop where he spends his time doing research, inventing things and writing books about them. He showed us a trick of floating aluminum pans off of a Tesla coil which I sadly did not get any pictures of. Next he got out a small vaccuum chamber and set some marshmallows in it. Yes they expand awesomely as the pressure declines, but what happens after that surprised me. Take a look: He also had a board which he had painted with homemade phosphorescent paint, made from ground-up strontium aluminate (I believe it was).  You could "draw" on it with a laser pointer: Here is an example of Franklin's bells, an electrical demonstration made famous by Benjamin Franklin.  A small metal clapper is suspended between two metal bells, each of which is hooked up to one end of an electrical circuit.  If sufficient voltage is passed through the circuit, the clapper is attracted to one bell, touches it, releases (or obtains) electrons to become similarly charged, whereupon it is repulsed.  It is then charged oppositely to the other bell and is attracted to it, until it touches that bell and swaps charges.  The cycle repeats as long as the circuit is maintained. The last thing we did was to eat whipped cream... that had been frozen in liquid nitrogen!  This turned Quinn into a dragon.

Posted by rachel 7 years ago


Thermochromic pigment - black - yellow - blue, 80cents aud per gram 20g/$16 and more

Hi, im starting over on ebay again selling thermochromic pigments among other things, but for some reason now my stuff doesnt appear on international sites/searches so, ebay is only really working out for me within australia, so ill just post some links here. http://www.ebay.com.au/sch/realjharrington/m.html?_nkw=&_armrs=1&_ipg=&_from= Thats my ebay listings, i sell thermochromic pigments in various colors, all changing at 31 celcius or body temp, all priced at 80 cents per gram (which is quite cheap, i dont turn a huge profit), i also have photochromic pigments in magenta/red and yellow, really bright really long lasting glow in the dark pigment (strontium aluminate or similar), soon ill be listing chameleon pigment once i paint a working demo, and also electroluminescent phosphor pigment, same deal, once i can show a demo. Also soon ill be selling moderate and very high powered spark gap ignitors, 5v ones arcing continuously 20mm, 30-80kv, and 15v ones which do some 7-10cm or more. Anyone interested can contact me over ebay, or instructables id rather do business directly through paypal than on ebay. Also im looking to collect bitcoins if anyone has any of those they want to buy in. I offer bulk rates for anything and everything i sell so just ask.

Posted by oldmanbeefjerky 2 years ago


Problems with my HXT HX5010 servo.

Hi,to whoever is reading this.I recently purchased a HXT HX5010 servo :http://www.hobbyking.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=22930 and i'm facing quite a few problems with it .I've never used a servo before so i really don't know how to trouble shoot it . first is that when i try the "sweep" program from the arduino examples,once it has reached 180 degrees,it  tries to go past the gear stopper and it takes it a few seconds to "realize" that it i sat 180 degrees and then only comes back to 0 degrees . the sweep program is:  #include Servo myservo;  // create servo object to control a servo                 // a maximum of eight servo objects can be created int pos = 0;    // variable to store the servo position void setup() {   myservo.attach(9);  // attaches the servo on pin 9 to the servo object } void loop() {   for(pos = 0; pos   {                                  // in steps of 1 degree     myservo.write(pos);              // tell servo to go to position in variable 'pos'     delay(15);                       // waits 15ms for the servo to reach the position   }   for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees   {                                    myservo.write(pos);              // tell servo to go to position in variable 'pos'     delay(15);                       // waits 15ms for the servo to reach the position   } } According to the program ,as soon as the servo reaches 180 degrees it is supposed to go back to 0 degrees however my servo first tries to go past the gear stopper and then only comes back to 0 degree.I am powering the servo with the 5v pin on the arduino.Should i use a external power supply for my arduino?I don't understand what the problem is .Please help me!

Asked by Strontium 4 years ago