2.(02.07 MC)

An x-ray has a wavelength of 4.18 Å. Calculate the energy (in J) of one photon of this radiation. Enter your answer in scientifi

Damm [24]

Answer:

E = 4.75 x 10⁻¹⁶ J

Explanation:

given,

wavelength of the x-ray , λ = 4.18 Å

Energy of photon = ?

we know

$E = \dfrac{hc}{\lambda}$

where h is the planks constant

c is the speed of light

h = 6.626 x 10⁻³⁴ m² kg / s

c = 3 x 10⁸ m/s

now,

$E = \dfrac{6.626\times 10^{-34}\times 3 \times 10^8}{4.18\times 10^{-10}}$

E = 4.75 x 10⁻¹⁶ J

hence, the energy of the photon is equal to E = 4.75 x 10⁻¹⁶ J

4 0

4 years ago

All the scientific theories used to explain the formation of the solar system are. . outdated. . imaginative. . non-testable. .

maria [59]

The correct answer for the statement “All the scientific theories used to explain the formation of the solar system are non-testable”. The answers outdated, imaginative and unacceptable are wrong. These theories are not proven and yet are not tested due to the complexity.

3 0

3 years ago

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Pam rubs a balloon on her head and then holds the balloon up against a wall. Why might the balloon stick to the wall?

gregori [183]

Answer:

It sticks to the wall due to electrostatics.

Explanation:

When pam rubs a balloon against his hair, and holds it up against the wall, he is basically adding a surplus of electrons which are negative charges to the surface of the balloon.

This motion would make the wall the more positively charged than the balloon. Therefore, when the two charges come in contact with each other, the balloon will stick to the wall because of the rule in electrostatics that opposite charges attract each other.

4 0

3 years ago

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A thin stream of water flows smoothly from a faucet and falls straight down. At one point the water is flowing at a speed of v1

MrRa [10]

Answer:

The vertical distance between these two points is 12.28 cm.

Explanation:

Given that,

Speed of water = 1.23 m/s

Diameter at lower point d'= 0.787 d

We need to calculate the speed of water

Using continuity equation

$A_{1}v_{1}=A_{2}v_{2}$

$\dfrac{\pi\times d^2}{4}v_{1}=\dfrac{\pi\times d'^2}{4}v_{2}$

$v_{2}=v_{1}\times(\dfrac{d}{d'})^2$

Put the value into the formula

$v_{2}=1.23\times(\dfrac{d}{0.787d})^2$

$v_{2}=1.98\ m/s$

We need to calculate the vertical distance h between these two points

Using Bernoulli theorem

$P_{1}+\dfrac{1}{2}\rho v_{1}^2+\rho gh_{1}=P_{2}+\dfrac{1}{2}\rho v_{2}^2+\rho gh_{2}$

Here, P₁ = P₂ = atmosphere pressure is same because both end is open

$\dfrac{1}{2}\rho(v_{2}^2-v_{1}^2)=\rho\times g(h_{1}-h_{2})$

$(v_{2}^2-v_{1}^2)=2g(h_{1}-h_{2})$

$2g\times\Delta h=(v_{2}^2-v_{1}^2)$

$\Delta h=\dfrac{1.98^2-1.23^2}{2\times9.8}$

$\Delta h=12.28\ cm$

Hence, The vertical distance between these two points is 12.28 cm.

6 0

4 years ago

A rocket moves upward, starting from rest with an acceleration of +29.4 for 3.98 s. it runs out of fuel at the end of the 3.98 s

topjm [15]

U = 0, initial upward speed
a = 29.4 m/s², acceleration up to 3.98 s
a = -9.8 m/s², acceleration after 3.98s

Let h₁ = the height at time t, for t ≤ 3.98 s
Let h₂ = the height at time t > 3.98 s

Motion for t ≤ 3.98 s:
h₁ = (1/2)*(29.4 m/s²)*(3.98 s)² = 232.854 m
Calculate the upward velocity at t = 3.98 s
v₁ = (29.4 m/s²)*(3.98 s) = 117.012 m/s

Motion for t > 3.98 s
At maximum height, the upward velocity is zero.
Calculate the extra distance traveled before the velocity is zero.
(117.012 m/s)² + 2*(-9.8 m/s²)*(h₂ m) = 0
h₂ = 698.562 m

The total height is
h₁ + h₂ = 232.854 + 698.562 = 931.416 m

Answer: 931.4 m (nearest tenth)

6 0

4 years ago

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