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Elden [556K]
2 years ago
11

2. a) A student obtained ice at 0°C from a refrigerator and placed it in a beaker on a

Physics
1 answer:
marin [14]2 years ago
6 0

Answer:

2 4

Explanation:

because

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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
Three +3.0-μC point charges are at the three corners of a square of side 0.50 m. The last corner is occupied by a −3.0-μC charge
Naddik [55]

Answer:

4.30 x 10⁵ N/C

Explanation:

Two positive +3.0-μC point charges at opposite corners of the square creates equal and opposite electric field at the center. hence the electric field by these two positive charges at opposite corners becomes zero.

a = length of the square of side = 0.50 m

r = distance of the center from each corner = \frac{a}{sqrt(2)} = \frac{0.50}{sqrt(2)} = 0.354 m

Magnitude of net electric field at the center is given as

E = \frac{2kq}{r^{2}} \\E = \frac{2(8.99\times10^{9})(3\times10^{-6})}{(0.354)^{2}} \\E = 4.30\times10^{5} NC^{-1}

6 0
3 years ago
A 71-kg swimmer dives horizontally off a 500-kg raft. If the diver's speed immediately after leaving the raft is 6m/s, what is t
Sloan [31]

Answer:

The answer is below

Explanation:

Momentum is used to measure the quantity of motion in an object. Momentum is the product of mass and velocity.

Momentum = mass * velocity

The principle of conservation of momentum states that momentum cannot be created or destroyed but  can be transferred. Therefore the momentum before and after an action is equal.

Initial momentum = Final momentum

Let m be the mass of the diver, M be the mass of the raft, u be the initial velocity of the diver, U be the initial velocity of the raft, v be the final velocity of the diver and V be the final velocity of the raft.

m = 71 kg, M = 500 kg, v = 6 m/s

Initial both the raft and diver are at rest, hence u and U is zero, hence:

mu + MU = mv + MV

71(0) + 500(0) = 71(6) + 500(V)

0 = 426 + 500(V)

500(V) = -426

V = -426/500

V = -0.852 m/s

5 0
2 years ago
how much current is in a circuit that includes a 9-volt battery and a bulb with a resistance of 3 ohms?
ExtremeBDS [4]
3 Amper 9 divided by 3
8 0
3 years ago
You are walking up an icy slope. suddenly your feet slip, and you start to slide backward. will you slide at a constant speed, o
Aleks04 [339]
You will accelerate down the slope.
6 0
3 years ago
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