Answer:

Explanation:
The question says that, "The closest star to the earth is 2 light years away. Calculate this distance in SI units".
Given that,
The distance between the closest star and the Earth is 2 light years.
The SI unit of distance is m. It means we need to convert light years to meters. We know that,

2 light-years means,

So, the required distance is equal to
.
Answer:
a) λ = 121.5 nm
, b) 102.6, 97, 91.1 nm
Explanation:
Bohr's model describes the energy of the hydrogen atom
= k² e² / 2m (1 / n²)
A transition occurs when the electron passes from n level to a lower one
-
= k² e² / 2m (1 /
² - 1 /
²)
Planck's relationship is
E = h f = h c / lam
hc /λ = k² e²/ 2m(1 /
² - 1 /
²)
1 / λ = [k² e² / 2m h c] (1 /
² - 1 /
²)
1 /λ = Ry] (1 /
² - 1 /
²)
a) the first element of the series occurs for
= 2
1 / λ = 1.097 10⁷ (1- 1/2²)
1 / λ = 1.097 10⁷ (1- 0.25)
1 / λ = 0.82275 10⁷
λ = 1.215 10⁻⁷ m
λ = 1,215 10⁻⁷ m (10⁹nm / m)
λ = 121.5 nm
b) the next elements of the series occur to
1 /λ λ (10-7m) λ (nm)
3 1 1,097 10⁷ (1-1 / 9) 1,0255 102.6
4 1 1,097 10⁷ (1-1 / 16) 0.9723 97.2
∞ 1 1,097 10⁷ (1 - 0) 0.91158 91.1
Answer:
E=1824.81 V/m
Explanation:
Given that
Voltage difference = 5 V
Distance ,D= 3 mm
θ = 24°
As we know that electric filed given as

Given that D is 24° with respect to the perpendicular to the electrodes.So we have to take cos component of D.
d= D cosθ
d= 3 cos24°
d = 2.74 mm
So


E=1824.81 V/m
Answer:
(A). The work done by friction in crossing the patch is -637.98 J.
(B). The speed of skier is 10.57 m/s.
Explanation:
Given that,
Mass of skier = 62 kg
Speed = 6.5 m/s
Length = 3.50 m
Coefficient kinetic friction = 0.30
Height = 2.5 m
(A) we need to calculate the work done by friction in crossing the patch
Using formula of work done

Put the value into the formula


The work done by friction in crossing the patch is -637.98 J.
(B) we need to calculate the speed of skier
Using conservation of energy


Final potential energy is zero
So, 

Put the value into the formula



The speed of skier is 10.57 m/s.
Hence, (A).The work done by friction in crossing the patch is -637.98 J.
(B).The speed of skier is 10.57 m/s.
The surface zone :)))))))))