Answer:
Sirius
Explanation:
On the HR diagram Sirius is the closet.
Answer:
T = 15.03°C
Explanation:
given data:
copper specific heat = Sc = 0.385 J/g °C
iron specific iron = Si = 0.450 J/g °C
specific heat of ethanol = Se = 2.46 J/g °C
net heat loss is equal to zero
![(m*S*\Delta T)_{copper} +(m*S*\Delta T)_ {iron} +(m*S*\Delta T)_ {ethanol} = 0](https://tex.z-dn.net/?f=%28m%2AS%2A%5CDelta%20T%29_%7Bcopper%7D%20%2B%28m%2AS%2A%5CDelta%20T%29_%20%7Biron%7D%20%2B%28m%2AS%2A%5CDelta%20T%29_%20%7Bethanol%7D%20%3D%200)
![150*0.385 *( T - (-50)) + 200*0.450*(T - 120) + 300*2.46 * (T -20) = 0](https://tex.z-dn.net/?f=150%2A0.385%20%2A%28%20T%20-%20%28-50%29%29%20%2B%20200%2A0.450%2A%28T%20-%20120%29%20%2B%20300%2A2.46%20%2A%20%28T%20-20%29%20%3D%200)
![57.75( T - (-50)) + 0.90(T - 120) +738(T -20) = 0](https://tex.z-dn.net/?f=57.75%28%20T%20-%20%28-50%29%29%20%2B%200.90%28T%20-%20120%29%20%2B738%28T%20-20%29%20%3D%200)
![57.75T + 2887.5 + 0.90T - 108 + 738T - 14760 = 0](https://tex.z-dn.net/?f=57.75T%20%2B%202887.5%20%2B%200.90T%20-%20108%20%2B%20738T%20-%2014760%20%3D%200)
![57.75T + 0.90T+738T = - 2887.5 + 108+14760](https://tex.z-dn.net/?f=57.75T%20%2B%200.90T%2B738T%20%3D%20-%202887.5%20%2B%20108%2B14760)
![796.65T= 11980.5](https://tex.z-dn.net/?f=796.65T%3D%2011980.5)
T = 15.03°C
Answer:
the potentail of kinetic and potential energy
Explanation:
first explain the concept of kinetic energy (what it is and what its used for) and give examples (cars, a basketball thrown across a hall, and airplane), and do the same with potential energy (the energy an object stores, example: a streched rubber band)
Answer:
b.) All these technologies use radio waves, including high-frequency microwaves
d.) Microwave ovens emit in the same frequency band as some wireless Internet devices.
e.) The radiation emitted by wireless Internet devices has the shortest wavelength of all the technologies listed above.
f.) All these technologies emit waves with a wavelength in the range of 0.10 to 10.0 m.
Explanation:
For option D. The frequency range of microwave ovens is 2450 MHz = 2.4 GHz, which intersects with wireless internet technology with range of 2.4 to 2.6 GHz.
For E, wavelenght and frequency are inversely proportional. Wireless internet service has the greatest frequency band and hence the shortest wavelenght band.
For F, in all these radiations, the highest Freq is 2.6 GHz and the lowest is 40 MHz. Wavelenght is speed of light (3x10^8 m/s) divided by the frequency.
2.6 GHz = 2.6x10^9 Hz
Wavelenght = 3x10^8 ÷ 2.6x10^9 = 0.1 m
40 MHz = 40x10^6
Wavelenght = 3x10^8 ÷ 40x10^6 = 7.5 m