An earth satellite in orbit emits a radio signal of constant frequency. compared to the emitted frequency, the frequency of the signal received by a stationary observer will appear to be:

a) higher as the satellite approaches
b) higher as the satellite moves away
c) lower as the satellite approaches
d) unaffected by the satellite's motion

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.