what is the displacement for a driver who travels 10 km to get to a point that is 4 km from his starting point

Pulsed dye lasers emit light of wavelength 585 nm in 0.45 ms pulses to remove skin blemishes such as birthmarks. The beam is usu

koban [17]

Answer:

a) E₀ = 2.125 eV, b) # photon2 = 9.2 10¹⁵ photons / mm²

Explanation:

a) To calculate the energy of a photon we use Planck's education

E = h f

And the ratio of the speed of light

c = λ f

We replace

E = h c /λ

Let's calculate

E₀ = 6.63 10⁻³⁴ 3 10⁸/585 10⁻⁹

E₀ = 3.40 10⁻¹⁹ J

Let's reduce

E₀ = 3.4 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)

E₀ = 2.125 eV

b) Let's look for the energy in each pulse

P = E / t

E = P t

E = 20.0 0.45 10⁻³

E = 9 10⁻³ J

let's use a ratio of proportions (rule of three) if we have the energy of a photon (E₀), to have the energy of 9 10⁻³ J

# photon = 9 10⁻³ /3.40 10⁻¹⁹

# photon = 2.65 10¹⁶ photons

Let's calculate the areas

Focus area

A₁ = π r²

A₁ = π (3.4/2)²

A₁ = 9,079 mm²2

Area requested for calculation r = 1 mm

A₂ = π 1²

A₂ = 3.1459 mm²

Let's use another rule of three. If we have 2.65 106 photons in an area A1 how many photons in an area A2

# photon2 = 2.65 10¹⁶ 3.1459 / 9.079

# photon2 = 9.2 10¹⁵ photons / mm²

8 0

2 years ago

A large piece of jewelry has a mass of 132.6 g. a graduated cylinder initially contains 48.6 ml water. when the jewelry is subme

Lerok [7]

The density of the substance is 10.5 g/cm³.

The jewelry is made out of Silver.

Density ρ is defined as the ratio of mass m of the substance to its volume V. The cylinder contains a volume V₁ of water and when the jewelry is immersed in it, the total volume of water and the jewelry is found to be V₂.

The volume V of the jewelry is given by,

$V=V_2 -V_1$

Substitute 48.6 ml for V₁ and 61.2 ml for V₂.

$V=V_2 -V_1\\ =61.2 ml -48.6 ml\\ =12.6 ml$

calculate the density ρ of the jewelry using the expression,

$\rho =\frac{m}{V}$

Substitute 132.6 g for m and 12.6 ml for V.

$\rho =\frac{m}{V}\\ =\frac{132.6 g}{12.6 ml} \\ =10.5 g/ml$

Since $1 ml=1 cm^3$ ,

The density of the jewelry is 10.5 g/cm³.

From standard tables, it can be seen that the substance used to make the jewelry is silver, which has a density 10.5 g/cm³.

4 0

3 years ago

A 200 g air-track glider is attached to a spring. The glider is pushed in 9.8 cm against the spring, then released. A student wi

Likurg_2 [28]

Answer:

k = 5.05 N/m

Explanation:

In order to calculate the spring mass of the system, you use the following formula:

$T=2\pi \sqrt{\frac{m}{k}}$ (1)

T: period of oscillation of the system

m: mass of the air-track glider = 200g = 0.200 kg

k: spring constant = ?

You first calculate the period of oscillation:

$T=\frac{1}{f}=\frac{1}{12/15.0s}=1.25s$

Next, you solve the equation (1) for k, and then you replace the values of the other parmateres:

$k=4\pi^2 \frac{m}{T^2}\\\\k=4\pi^2 \frac{0.200kg}{(1.25s)^2}=5.05\frac{N}{m}$

The spring constant of the spring is 5.05 N/m

6 0

2 years ago

Biologists use ball-and-stick models to study complex molecules by representing atoms with balls and bonds with sticks. DNA is a

AleksAgata [21]

One of the major limitations of using the ball and stick model for DNA, is that within a single double stranded segment of DNA, one would have to use many many balls to represent atoms that are present in the sugar phosphate backbone, along with all of the main atoms that compose the nitrogenous bases of DNA, we also cannot construct or show the helical form of DNA, by using balls and sticks as well.

7 0

3 years ago

What is: the fastest car the fastest animal the fastest human the fastest aeroplane

seropon [69]

The Hennessey Venom GT is the fastest road car in the world.
The fastest land animal is the Cheetah
Usain Bolt, the World's fastest man.
The Lockheed SR-71 "Blackbird" the fastest airplane.

4 0

3 years ago

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what is the displacement for a driver who travels 10 km to get to a point that is 4 km from his starting point​

what is the displacement for a driver who travels 10 km to get to a point that is 4 km from his starting point