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3 years ago

What characteristic describes what happens during a physical change

Physics

1 answer:

Alex73 [517]3 years ago

7 0

Physical change changes the form of a chemical substance

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A cork has weight mg and density 25% of water’s density. A string is tied around the cork and attached to the bottom of a water-

yuradex [85]

Answer:

Explanation:

Given

Density of Cork $\rho _c=0.25\rho _{water}$

Considering V be the volume of Cork

Buoyant Force will be acting Upward and Weight is acting Downward along with T

Since density of water is more than cork therefore Cork will try to escape out of water but due to tension it will not

we can write as

$\rho _{water}Vg-\rho _Cvg-T=0$

where T=tension

Thus Tension T is

$T=Vg(\rho _{water}-\rho _c)$

Taking $\rho _c$ common

$T=\rho _cVg(\frac{\rho _{water}}{\rho _c}-1)$

$T=mg(\frac{\rho _{water}}{\rho _c}-1)$

$T=mg(4-1)$

$T=3mg$

4 0

3 years ago

According to the Big Bang theory, when the universe first formed, the temperature was extremely hot. As it began to cool, proton

alex41 [277]

hydrogen would be the first Element

5 0

4 years ago

The particles ejected from the sun during a coronal mass ejection is called

ipn [44]

Answer:

Plasma

Explanation:

A Coronal Mass Ejection (CME) is an outburst of energy that occurs near the outer part of the sun's atmosphere which causes a production of plasma along with a magnetic field.

The outermost part of the sun's atmosphere is called the Solar Corona Although difficult to see, the corona can be seen during a total solar eclipse.

Plasma from CME are clouds of magnetized electrically charged particles which the solar wind causes to travel at a speed of 1.6 million km/hr.

7 0

3 years ago

Two concentric current loops lie in the same plane. The outer loop has twice the diameter of the inner loop. The inner loop carr

Flauer [41]

Answer: The outer loop should carry a current of 2.0 A.

The current should flow in the counter-clockwise direction

Explanation: Please see the attachments below

7 0

3 years ago

A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V?What is the total energy stores in the

Rama09 [41]

1) $1.11\cdot 10^{-7} J$

The capacitance of a parallel-plate capacitor is given by:

$C=\frac{\epsilon_0 A}{d}$

where

$\epsilon_0$ is the vacuum permittivity

A is the area of each plate

d is the distance between the plates

Here, the radius of each plate is

$r=\frac{2.0 cm}{2}=1.0 cm=0.01 m$

so the area is

$A=\pi r^2 = \pi (0.01 m)^2=3.14\cdot 10^{-4} m^2$

While the separation between the plates is

$d=0.50 mm=5\cdot 10^{-4} m$

So the capacitance is

$C=\frac{(8.85\cdot 10^{-12} F/m)(3.14\cdot 10^{-4} m^2)}{5\cdot 10^{-4} m}=5.56\cdot 10^{-12} F$

And now we can find the energy stored,which is given by:

$U=\frac{1}{2}CV^2=\frac{1}{2}(5.56\cdot 10^{-12} F/m)(200 V)^2=1.11\cdot 10^{-7} J$

2) 0.71 J/m^3

The magnitude of the electric field is given by

$E=\frac{V}{d}=\frac{200 V}{5\cdot 10^{-4} m}=4\cdot 10^5 V/m$

and the energy density of the electric field is given by

$u=\frac{1}{2}\epsilon_0 E^2$

and using

$E=4\cdot 10^5 V/m$ , we find

$u=\frac{1}{2}(8.85\cdot 10^{-12} F/m)(4\cdot 10^5 V/m)^2=0.71 J/m^3$

7 0

4 years ago