Answer:
Frequency is the number of wavelengths, which is measured in hertz.
Explanation:
I have my ways ;)
Answer:
Food Chain. A food chain shows you how one organism eats another and transfers its energy. For example, a zebra eats grass, and the zebra is eaten by the lion.
Answer:
The star-sphere discovered by the Greeks and other ancient civilizations which shows the physical location in space of the nearby stars.
Explanation:
The celestial sphere is an ideal sphere, without defined radius, concentric with the terrestrial globe, in which the stars apparently move. Some ancient civilizations such as the Greeks assumed that the stars were attached to a celestial sphere, which revolves around the earth, while our planet is always immobile.
Answer:
a) 4.9W b) 3.82W
Explanation:
Stefan-Boltzmann law of radiation formulae:
Q/t (W) = sigma* e*A*T^4
Sigma = 5.67*10^-8 j/sm^2K^4 (Stefano Boltzmann constant)
e = emissivity
T = absolute temperature in kelvin and A = area in m^2
a) Q/t = 140/10000(m^2) * 0.87* 5.67* 10^-8* (290^4) = 4.9W
b) without hair the
Q/t = 140/ 10000(m^2) *0.68* 5.67* 10^-8* (290^4)
= 3.82W
