In this paper :
Light is Heavy
the following is claimed:
"the speed of light appears to be equal for all observers"
How can this be true if astronomers rely on the doppler shift to determine if an electromagnetic source is moving away or closer to the earth?
How does this tie in with...
Momentum is also the rate of change of force. This can easily be verified by rearranging the equations:
force = mass * acceleration
acceleration = velocity / seconds
momentum = mass * velocity,
Therefore:
momentum = force * seconds
Edited typo.
Integral
If resistors of 5 ohm, 20 ohm, 40 ohm, and 50 ohms are parallel with each other, the equivalent resistance would most nearly be how many ohms?
Well, do you have options? Sounds like a multiple choice question. Nearly how many ohms?
try 1/Rx = 1/R1 + 1/R2 + 1/R3 +1/Retc... !
PIC's are a great way to get into embedded control. You can control all sorts of stuff, with very little circuit effort. Start with a PIC16F84, read the data sheet from Microchip.
You can start off programming with PIC assembler, but I advice moving to 'C'. CCS have a basic C compiler, and...
What type of motor are you referring to, large AC, a DC motor, small motors or Stepper type motors. They all have different characteristics.
What is your application? AC and DC motors can deliver a lot of torque for their size, but remember for mobile applications, they require a lot of...
Wiring same rated lights in series is the way to do it. .. But, the alternator or generator on your truck can only supply a limited amount of current, and if you are drawing more current than the alternator can supply while the engine is on, the rest of the current will come from the battery...
PS, the capacitor on the output of the 7812 is to supply any sudden power requirements from whatever is connected to it so that the voltage does not fall off, not to prevent damage to the chip! I.e. is surpresses ripples in the supply. And by motor, hope you mean the CD motor dduardo.
More than 5A for a CD player, unlikey.
I note Peter that you mentioned lights. Are these 12V spots on the outside of the truck. If so, then you can wire two similar rated lights in series and connect them directly to the 24V supply. If they are rated the same, then they will have similar...
The following assumes that the magnet is not close enough and strong enough to suck in and hold the ball. If this is the case then some interesting things happen.
The magnet will exert an upwards force on the ball as it approaches, countering some of the weight force, which will result in...
Using an appropriate fuse on local end equipment is advised in all circumstances.
Undersizing fuses at a distribution level can result in un-necessary outages. If a 100A fuse were to be used in a substation that normally supplies 80 amps to a number of houses that have 200A main fuses...
Under no circumstances would I suggest a resistor drop for items such as CD players. The power requirements for such devices is not continious, and the rated power of the devices, e.g. 1A, is the maximum, not continious. A CD player requires more power when the motor is going, for example when a...
You could try replacing the pot with a digitally controlled pot and using a microcontroller take switch inputs and control the pot. For this you would need some software for the controller and some nice looking dash mounted switches. This is all a lot of hassle, and would take some time to...