Choice 1
The Sun's radiation and solar wind cause the dust and gas around the comet (coma) to stretch the coma. The solar wind electromagnetically blows the ions in the coma away.
Answer
given,
mass = 100 kg
acceleration = 10 m/s²
A mass 20 kg slides over 100 kg block
acceleration = 3 m/s²
horizontal friction exerted by the 100 kg block on 20 kg
using newton's second law
F - f = 0
F = f
f = ma
f = 20 × 3
f = 60 N
now net force acting on the 100 kg block
F_net = m a
F_net = 100 x 10
F_net = 1000 N
after 20 kg block falls the acceleration of the bock
F = 1000 +60
F = 1060 N
acceleartion on the block
![a = \dfrac{F}{m}](https://tex.z-dn.net/?f=a%20%3D%20%5Cdfrac%7BF%7D%7Bm%7D)
![a = \dfrac{1060}{100}](https://tex.z-dn.net/?f=a%20%3D%20%5Cdfrac%7B1060%7D%7B100%7D)
a = 10.60 m/s²
<span> the </span>electric field<span> direction about a </span>positive<span> source </span>charge<span> is always directed away from the </span>positive<span> source. And the </span>electric field <span>direction about a negative source </span>charge<span> is always directed toward the negative source.</span>
Answer
Applying Wein's displacement
![\lamda_{max}\ T = 2898 \mu_mK](https://tex.z-dn.net/?f=%5Clamda_%7Bmax%7D%5C%20T%20%3D%202898%20%5Cmu_mK)
1) for sun T = 5800 K
![\lambda_{max} = \dfrac{2898}{5800}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cdfrac%7B2898%7D%7B5800%7D)
![\lambda_{max} = 0.5 \mu_m](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%200.5%20%5Cmu_m)
2) for tungsten T = 2500 K
![\lambda_{max} = \dfrac{2898}{2500}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cdfrac%7B2898%7D%7B2500%7D)
![\lambda_{max} = 1.16 \mu_m](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%201.16%20%5Cmu_m)
3) for heated metal T = 1500 K
![\lambda_{max} = \dfrac{2898}{1500}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cdfrac%7B2898%7D%7B1500%7D)
![\lambda_{max} = 1.93 \mu_m](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%201.93%20%5Cmu_m)
4) for human skin T = 305 K
![\lambda_{max} = \dfrac{2898}{305}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cdfrac%7B2898%7D%7B305%7D)
![\lambda_{max} = 9.50 \mu_m](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%209.50%20%5Cmu_m)
5) for cryogenically cooled metal T = 60 K
![\lambda_{max} = \dfrac{2898}{60}](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%20%5Cdfrac%7B2898%7D%7B60%7D)
![\lambda_{max} = 48.3 \mu_m](https://tex.z-dn.net/?f=%5Clambda_%7Bmax%7D%20%3D%2048.3%20%5Cmu_m)
range of different spectrum
UV ----0.01-0.4
visible----0.4-0.7
infrared------0.7-100
for sun T = 5800
λ 0.01 0.4 0.7 100
λT 58 2320 4060 5.8 x 10⁵
F 0 0.125 0.491 1
fractions
for UV = 0.125
for visible = 0.441-0.125 = 0.366
for infrared = 1 -0.491 = 0.509