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3 years ago

How many core electrons does calcium have ?

Physics

2 answers:

frutty [35]3 years ago

8 0

I think 25 I’m not sure

Shtirlitz [24]3 years ago

4 0

25 hope this helped

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A technique in which the muscles are stretched by an outside force is called _____.

geniusboy [140]

A technique in which the muscles are stretched by an outside force is called Passive Stretching

6 0

3 years ago

Some instruments differentiate individual quanta of electromagnetic radiation based on their energies. assume such an instrument

lesya [120]

There is a relationship between the energy of a photon and its wavelength. This can be expressed as a mathematical equation shown below:

E = hc/λ
where
h is the Planck's constant equal to 6.62607004 × 10⁻³⁴ m²<span> kg / s
c is the speed of light equal to 3</span>× 10⁸ m/s
λ is the wavelength

3.5×10⁻¹⁶ J = (6.62607004 × 10⁻³⁴ m² kg / s)(3× 10⁸ m/s)/λ
Solving for λ,
λ = 56.8×10⁻⁹ m or<em> 56.8 nm</em>

5 0

4 years ago

A light wave with an electric field amplitude of E0 and a phase constant of zero is to be combined with one of the following wav

Anarel [89]

Answer:

the greatest intensity is obtained from c

Explanation:

An electromagnetic wave stagnant by the expression

E = E₀ sin (kx -wt)

when two waves meet their electric fields add up

E_total = E₁ + E₂

the intensity is

I = E_total . E_total

I = E₁² + E₂² + 2E₁ E₂ cos θ

where θ is the phase angle between the two rays

Let's examine the two waves

in this case E₁ = E₂ = E₀

I = Eo2 + Eo2 + 2 E₀ E₀ coasts

I = E₀² (2 + 2 cos θ )

I = 2 I₀ (1 + cos θ )

let's apply this expression to different cases

a) In this case the angle is zero therefore the cosine is worth 1 and the intensity is I_total = 4 I₀

b) cos π = -1 this implies that I_total = 0

c) the cosine is 1,

I = E₀² + 4E₀² + 2 E₀ (2E₀) cos θ

I = E₀² (5 +4 cos θ)

I = E₀² 9

I = 9 Io

d) in this case the cos pi = -1

I = E₀² (5 -4)

I = I₀

e) we rewrite the equation

I = E₀² + 9 E₀² + 2 E₀ (3E₀) cos θ

I = Eo2 (10 + 6 cos θ)

cos π = -1

I = E₀² (10-6)

I = 4 I₀

the greatest intensity is obtained from c

3 0

3 years ago

A weightlifter works out at the gym each day. Part of her routine is to lie on her back and lift a 43 kg barbell straight up fro

Tasya [4]

Answer:

A. 231.77 J

B. 5330.71 J

C. 46 donuts

Explanation:

A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:

W = F * d

Where the force is the weight of the barbell.

F = m * g

Hence, the work done in lifting the barbell is:

W = m * g * d

W = 43 * 9.8 * 0.55

W = 231.77 J

B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:

E = 23 * m * g * d

E = 23 * 231.77

E = 5330.71 J

C. 1 Joule = 4.184 calories

5330.71 Joules = 5330.71 * 4.184 = 22303.69

If 1 donut contains 490 calories, the number of donuts she will need will be:

N = 22303.69/490 = 45.5 donuts or 46 donuts

5 0

4 years ago

A railroad car of mass 2,000 kg traveling at a velocity v = 10 m/s is stopped at the end of the tracks by a spring-damper system

Murrr4er [49]

Stopped at the end of the tracks by a spg-damper system, as shown in fig. 1

6 0

3 years ago