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3 years ago

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Physics

1 answer:

svlad2 [7]3 years ago

4 0

Q #1: Oceanic crust is usually more active than continental. They also differ in thickness, density, age, and chemical composition.
Q #2: Hot fluid material that resides within the earth's crust from which lava and other igneous rocks are developed. <span>Q #3: Folded mountains are formed when two tectonic plates move together. This special movement of the two plates compels sedimentary rocks upwards, which results in folds. </span>

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A cube of wood is floating on water. a cube of iron is totally submerged in water. the cubes are equal in volume. which cube has

-BARSIC- [3]

The one that's completely submerged is displacing more water, so the buoyant force on it is greater.

5 0

3 years ago

Make a list of principle of lever.

vivado [14]

Answer:

The force applied to make the object move

8 0

3 years ago

Read 2 more answers

0.45 kg soccer ball changes its velocity by 20.0 m/s due to a force applied to it in 0.10 seconds. What force was necessary for

Paladinen [302]

Assuming the accleration applied was constant, we have

$v=v_0+at\implies v_0+20.0\,\dfrac{\mathrm m}{\mathrm s}=v_0+a(0.10\,\mathrm s)$

$\implies20.0\,\dfrac{\mathrm m}{\mathrm s}=a(0.10\,\mathrm s)$

$\implies a=200\,\dfrac{\mathrm m}{\mathrm s^2}$

Then the force applied to the ball is given by

$F=ma=(0.45\,\mathrm{kg})\left(200\,\dfrac{\mathrm m}{\mathrm s^2}\right)$

$\implies F=90\,\dfrac{\mathrm{kg}\,\mathrm m}{\mathrm s^2}=90.\,\mathrm N$

8 0

3 years ago

A wind turbine is rotating counterclockwise at 0.626 rev/s and slows to a stop in 12.9 s. Its blades are 17.9 m in length. What

iogann1982 [59]

Answer:

276.5 m/s^2

Explanation:

The initial angular velocity of the turbine is

$\omega=0.626 rev/s \cdot 2\pi rad/rev =3.93 rad/s$

The length of the blade is

r = 17.9 m

So the centripetal acceleration is given by

$a=\omega^2 r$

At the instant t = 0,

$\omega=3.93 rad/s$

So the centripetal acceleration of the tip of the blades is

$a=(3.93 rad/s)^2 (17.9 m)=276.5 m/s^2$

5 0

3 years ago

The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on

sashaice [31]

To solve this problem we can apply the concept related to thermal expansion, including the analogy with resistance and final intensity.

The mathematical expression that describes the expansion of a material by a thermal process is given by

$R = R_0\alpha \Delta T$

Where

$R_0$ = Initial resistance

$\alpha =$ Thermal expansion coefficient

$\Delta T =$ Change in the temperature

If we want to directly obtain the final value of the resistance of the object, you would simply add the initial resistance to this equation - because at this moment we have the result of how much resistance changed, but not of its final resistance - So,

$R_f = R_0 + L_0\alpha \Delta T$

$R_f = R_0(1 + \alpha \Delta T)$

Re-arrange to find the change at the temperature,

$\Delta T=\frac{1}{\alpha}\frac{R_f}{R_0}-1}$

Since the resistance is inversely proportional to the current and considering that the voltage is constant then

$R \propto \frac{1}{I}$

Then,

$\Delta T=\frac{1}{\alpha}\frac{I_0}{I_f}-1}$

$\Delta T = \frac{1}{4.5*10^{-3}}(\frac{I_0}{I_0/8}-1)$

$\Delta T = \frac{1}{4.5*10^{-3}}(8-1)$

$\Delta T = 1555.5k$

<em>(It is possible that there is a typing error and the value is not 4.5 but 4.3, so the closest approximate result would be 1627K and mark this as the correct answer)</em>

6 0

3 years ago