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3 years ago

The isotope cobalt-60 has a nuclear mass of 59.933820 u

1 answer:

3 0

Cobalt has an atomic number (Z) of 27, which means the nuclei of all its isotopes have 27 protons. Cobalt 60 has an atomic mass of 60, so it has 60-27 = 33 neutrons.

The mass of 27 isolated protons plus the mass of 33 isolated neutrons would be:

27*(1.007825 u) + 33*(1.008665 u) = 60.497220 u

The actual mass of the nucleus of 60-Co is 59.933820 u.

Mass defect: 60.497220 u - 59.933820 u = 0.563400 u

The mass defect is equal to the binding energy of a nucleus.
using the fact that 1 u = 931.5 MeV/c^2

(0.563400 u)*(931.5 MeV/u) = 524.807 MeV

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Solve for c in the proportion. 6/c = 48/40 c= ?

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Answer:

5 should be correct answer

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3 years ago

Solve the following system of equations: x − 2y = 5 2x − 4y = 10

emmasim [6.3K]

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3 years ago

Which are the solutions of x2 = –5x + 8?

Nostrana [21]

Answer:

As exact answers:

$x=\frac{-5-\sqrt{57} }{2}$ and $x=\frac{-5+\sqrt{57} }{2}$

As decimal answers:

x = -6.2749172 ≈-6.3

x = 1.27491722 ≈ 1.3

Step-by-step explanation:

For quadratic equations, you can use the quadratic formula. Rearrange the equation to standard from, which is ax² + bx + c = 0.

x² = –5x + 8

x² + 5x - 8 = 0

State the values for "a", "b" and "c",

a = 1; b = 5; c = -8

$x=\frac{-b±\sqrt{b^{2}-4ac} }{2a}$ (Ignore the Â, it's a formatting error)

$x=\frac{-5±\sqrt{5^{2}-4(1)(-8)} }{2(1)}$ Simplify

$x=\frac{-5±\sqrt{25-(-32)} }{2}$ Two negatives make a positive

$x=\frac{-5±\sqrt{57} }{2}$

Split the equation at the ± for plus and minus:

$x=\frac{-5+\sqrt{57} }{2}$ = 1.27491722 ≈ 1.3

$x=\frac{-5-\sqrt{57} }{2}$ = -6.2749172 ≈ -6.3

Therefore the solutions are 1.3 and -6.3.

6 0

3 years ago

A two-dimensional vector has an x-component of 10.3~\text{meters}10.3 meters and a y-component of 4.30~\text{meters}4.30 meters.

Georgia [21]

9514 1404 393

Answer:

23°

Step-by-step explanation:

The angle a vector makes relative to the +x axis is found as ...

α = arctan(y/x) = arctan(4.30/10.3) ≈ 22.66°

The angle is about 23°.

Additional comment

This vector resides in the first quadrant, so no adjustment of the angle is needed. In other quadrants, 180° may need to be added or subtracted from the angle given by the arctan function to arrive at the correct value. (Some calculators and spreadsheets have an ATAN2(x, y) function that takes signs into account.)

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3 years ago

Twice the sum of 13 and x is not greater than 15

Kobotan [32]

Answer:

x = 0

Step-by-step explanation:

This is saying that 2(13x) < 15

If you have 2[13(0)] < 15

It will come to 2(0) < 15

This equals 0 < 15 which is true therefore making the x value = 0

7 0

3 years ago