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3 years ago

Find the radius to which the sun must be compressed for it to become a black hole.

Physics

1 answer:

timofeeve [1]3 years ago

7 0

Answer:

2950 m

Explanation:

The radius to which the sun must be compressed to become a black hole is equal to the Schwarzschild radius, defined as:

$R=\frac{2GM}{c^2}$

where

G is the gravitational constant

M is the of the sun

c is the speed of light

The mass of the sun is

$M=1.99\cdot 10^{30}kg$

So, if we substitute the values of the other constants inside the formula, we find the value of the Schwarzschild radius for the sun:

$R=\frac{2(6.67\cdot 10^{-11} m^3 kg^{-1}s^{-2})(1.99\cdot 10^{30} kg)}{(3\cdot 10^8 m/s)^2}=2950 m$

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A spider twirls a 25 mg fruit fly around in a circle with radius 17.6 cm at the end of a web. If the velocity of the fly is 110

olchik [2.2K]

Answer:

Fc = 1.7x10^-4 N

Explanation:

Convert everything to proper units:

m = 25mg = 2.5x10^-5 kg

r = 17.6cm = 0.176m

v = 110cm/s = 1.1m/s

the formula for centripetal force is Fc = mv^2 / r

Plug everything and solve for Fc;

fc = (2.5x10^-5)(1.1^2) / 0.176

Fc = 1.7x10^-4 N

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4 years ago

What are radioactive isotopes?

melisa1 [442]

Answer:

Radioactive isotope , also called radioisotope,

radionuclide, or radioactive nuclide, any of

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gamma rays .

A brief treatment of radioactive isotopes follows.

For full treatment, see isotope: Radioactive

Radioactiveisotopes.

Every chemical element has one or more

radioactive isotopes. For example, hydrogen, the

lightest element, has three isotopes with mass

numbers 1, 2, and 3. Only hydrogen-3 (tritium ),

however, is a radioactive isotope , the other two

being stable. More than 1,000 radioactive

isotopes of the various elements are known.

Approximately 50 of these are found in nature;

the rest are produced artificially as the direct

products of nuclear reactions or indirectly as the

radioactive descendants of these products.

Radioactive isotopes have many useful

applications. In medicine , for example, cobalt -60

is extensively employed as a radiation source to

arrest the development of cancer. Other

radioactive isotopes are used as tracers for

diagnostic purposes as well as in research on

metabolic processes. When a radioactive isotope

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quantities of the stable element, it behaves

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Iodine -131 has proved effective in treating

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Explanation:

#learnwithbrainly

8 0

3 years ago

A solid conducting sphere (radius = 5.0 cm) has a charge of 0.25 nC distributed uniformly on its surface. If point A is located

nadezda [96]

Answer:

$\Delta V = 30V$

Explanation:

give data:

inside diameter = 5.0 cm

charge q = 0.25 nC

Outside diameter = 15 cm

potential V at inside sphere is = $V=\frac{kq}{R}$

potential V at outside sphere is = $V=\frac{kq}{r}$

k is constant whose value is = $8.99 *10^{9}Nm^{2}/c^2$

then potential difference between two point is

$\Delta V = kq \left [\frac{1}{R}-\frac{1}{r} \right ]$

$\Delta V = 9*10^{9}*0.25*10^{-9} \left [\frac{1}{0.05}-\frac{1}{0.15} \right ]$

$\Delta V = 30V$

6 0

4 years ago

A 1.30-kg object is held 1.10 m above a relaxed, massless vertical spring with a force constant of 315 N/m. The object is droppe

pshichka [43]

Answer:

0.345m

Explanation:

Let x (m) be the length that the spring is compress. If we take the point where the spring is compressed as a reference point, then the distance from that point to point where the ball is held is x + 1.1 m.

And so the potential energy of the object at the held point is:

$E_p = mgh$

where m = 1.3 kg is the object mass, g = 10m/s2 is the gravitational acceleration and h = x + 1.1 m is the height of the object with respect to the reference point

$E_p = 1.3 * 10 * (x + 1.1) = 13(x + 1.1) = 13x + 14.3 J$