155Ω
Explanation:
R = R ref ( 1 + ∝ ( T - Tref)
where R = conduction resistance at temperature T
R ref = conductor resistance at reference temperature
∝ = temperature coefficient of resistance for conductor
T = conduction temperature in degrees Celsius
T ref = reference temperature that ∝ is specified at for the conductor material
T = 600 k - 273 k = 327 °C
Tref = 300 - 273 K = 27 °C
R = 50 Ω ( 1 + 0.007 ( 327 - 27) )
R = 155Ω
Answer: 24.7 km/h
Explanation:
1) Average speed definition and formula
The average speed is the total distance run divided by the time elapsed:
S = distance / time
2) Distance 1 = 67 km
3) Distance 2 = 81 km
4) Total distance traveled = 67 km + 81 km = 148 km
5) time 1 = 1 hour
6) time 2 = 5 hours
7) total time = time 1 + time 2 = 1 h + 5 h = 6 h
8) Average speed:
S = 148 km / 6 h = 24.7 km/h
Answer:
Explanation:
The definition of the intensity in terms of power is given by:
Where:
- P is the power
- A is the area
If the sound emits uniformly in all directions and that there are no reflections, we can assume the geometry of the wave sound is spherical.
Let's recall the area of a sphere is 
To the first location we have:
and to the second location we have:
Now, we can divide each intensity to find the second intensity.
I hope it helps you!
Answer:
(a) 
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:
where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:
(b)
Now, for 90% radiator blackbody at 2000 K:
<u>P = 0.816 Watt</u>
Answer:
c
Explanation:
Green house effect:
Temperature of atmosphere is going to increased continuously, because infrared light absorbed by gas .This increased in temperature atmosphere is called green house effect.
The green houses gases are as follows
,Carbon diaoxide,water vapor ,,Carbon diaoxide ,Methane ,,Carbon diaoxide oxide,CFCs ,ozone.
So the option c is correct.
