Recent content by GoatGuy

  1. GoatGuy

    High School Why a mug handle gets very hot when microwaved

    Funny thing... I was vacationing a few weeks ago, and the rented-beach-pad had a bunch of ceramic coffee mugs waiting to be used. It was 4 AM the following day, and rather than make a fresh pot of coffee, I thought I'd just microwave the last bit in the pot. In it went, set the timer on 2...
  2. GoatGuy

    In a car ignition how does a circuit work?

    While you are right about the energy-of-the-spark peaking just after strike, there is a substantial amount of potential energy at that same time in the condenser. As the (rapidly decreasing) energy sloshes between condenser and coil primary, it continues to excite the now-struck arc on the...
  3. GoatGuy

    Automatic Voltage regulator rating

    Sometimes it pays to figure out what is in your microwave... We have an Amana brand (1990s),which inside has a large transformer (DANGER! DANGER!) and a set of primary wires that are hooked in series for 220 V operation, but in parallel for 110 V operation. With a screwdriver, you can...
  4. GoatGuy

    In a car ignition how does a circuit work?

    The capacitor is NOT for ''noise suppression'', although it does serve that purpose. It is to act as the C part of the LC tank circuit formed, allowing the current to ring between primary coil and the capacitor, back and forth like the sloshing of water in a bathtub. This back-and-forth...
  5. GoatGuy

    Undergrad What does power have to do with the speed calculations of a Train?

    Tim… some basic physics will help. Nº 1: E = ½ mv² Nº 2: E = ∫ P(t) dt Nº 3: P = mva (very useful for moving bodies) Nº 4: d = ½ at² (sometimes very useful, but has initial conditions to work) Nº 4a: d = ½ at² + v₀t (including initial velocity) E is ENERGY. P is POWER. Big difference...