# Search results

1. ### 555 timer

Can you tell me what is wrong with my timer. I want it to make a relay open and shut periodically. For some reason it's not working.
2. ### Creating an electric field

I want to create an electric field that will cause a copper BB to move. So far I have tried using a 9V battery with the positive end attached to a metal sheet and the negative attached to another sheet, like a capacitor. Unfortunately this hasn't worked. Any ideas?
3. ### Microwave Optics

This is a question I came across in lab. I inserted a reflecter between a microwave transmitter and receptor, with the plane of the reflector parallel the the axis of the beam. The reflector is then moved away. See the setup and data plot in the attachment. I understand that the waves...
4. ### Definite Integral

Homework Statement solve the integral: ∫_(-∞)^∞▒〖x^2 e^(-λ(x-a)^2 ) 〗 dx where λ and a are positive real constants The Attempt at a Solution I tried integration by parts with and without y-substitution but neither worked for me. Without substitution, I set up the integral to look...
5. ### 555 & 556 timers

I'm planning on using a 556 timer for a 3-way solenoid valve. I need to have both valves closed for a period of 10 seconds, then open the first valve for 20 ms, followed by the opening of the second valve for 20 ms. This is astable. Is it possible to line up the timing using a 556 timer or do...
6. ### Potential Due to a Collection Charges

My text reads for Potential Due to a Collection Charges: 1/(4πє) ∑ q/r I'm consfused about the distance and how it's treated as a scalar. Let's say you want to calculated the potential between two protons. If a proton (or electron) is placed in the middle, there will be no net force...
7. ### Potential Due to a Collection Charges

My text reads for Potential Due to a Collection Charges: 1/(4πє) ∑ q/r Lets say you want to calculate the potential between two charges. Do you take the magnitude of the distance (r) or do you account for their direction of the charges with respect to the field point. Based on the...