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If a water wave oscillates up and down three times each second and the distance between wave crests is 2 m, wh?
Q no 1: If a water wave oscillates up and down three times each second and the distance between wave crests is 2 m, what is its frequency? What is its wavelength? What is its wave speed?
Q no 2: A transformer has N1 = 350 turns and N2 = 2 000 turns. If the input voltage is delta
v(t) = (170 V) cos wt, what rms voltage is developed across the secondary coil?
Q no 3: We don't notice the de Broglie wavelength for a pitched baseball. Is this because
the wavelength is very large or because it is very small?
Q no 4: In a cool room, a metal or marble table top feels much colder to the touch than does a wood surface even though they are at the same temperature. Why?
Hints, not answers...
1. Frequency is number of oscillations per second. Note this phrase: "oscillates up and down three times each second". Can you get from that the number of oscillations per second?
Wavelength is the distance between crests. Note this phrase: "distance between wave crests is 2 m". Can you get from that the distance between crests?
Speed is wavelength x frequency.
2. output/input = N2/N1.
RMS voltage is sqrt(2)/2 times the peak voltage.
3. Calculate it. Then decide if you have a large number or a small number.
4. It has to do with conductivity of heat.
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