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2 years ago

Which of the following is a good thermal insulator?* Iron Styrofoam Silver Graphite

Physics

2 answers:

Goryan [66]2 years ago

7 0

Answer: graphite

Explanation:

igor_vitrenko [27]2 years ago

6 0

A good thermal insulator is iron

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A block of wood is floating in water; it is depressed slightly and then released to oscillate up and down. Assume that the top a

Marysya12 [62]

Explanation:

Equilibrium position in y direction:

W = Fb (Weight of the block is equal to buoyant force)

m*g = V*p*g

V under water = A*h

hence,

m = A*h*p

Using Newton 2nd Law

$-m*\frac{d^2y}{dt^2} = Fb - W\\\\-m*\frac{d^2y}{dt^2} = p*g*(h+y)*A - A*h*p*g\\\\-A*h*p*\frac{d^2y}{dt^2} = y *p*A*g\\\\\frac{d^2y}{dt^2} + \frac{g}{h} * y =0$

Hence, T time period

T = 2*pi*sqrt ( h / g )

4 0

3 years ago

Really confused on this. Any help will be great

pav-90 [236]

C is what i would go with

8 0

2 years ago

Assume that the average mass of each of the approximately 1 billion people in China is 55 kg.Assume that they all gather in one

Harman [31]

Answer: $5.9(10)^{-8} m$

Explanation:

The equation to calculate the center of mass $C_{M}$ of a particle system is:

$C_{M}=\frac{m_{1}r_{1}+m_{1}r_{1}+...+m_{n}r_{n}}{m_{1}+m_{2}+...+m_{n}}$

In this case we can arrange for one dimension, assuming the geometric center of the Earth and the ladder are on a line, and assuming original center of mass located at the Earth's geometric center:

$C_{M}=\frac{m_{E}(0 m) + m_{p} r_{E-p}}{m_{E}+m_{p}}$

Where:

$m_{E}=5.9(10)^{24} kg$ is the mass of the Earth

$m_{p}=55(10)^{9} kg$ is the mass of 1 billion people

$r_{E}=6371000 m$ is the radius of the Earth

$r_{E-p}=6371000 m- 2m=6370998 m$ is the distance between the center of the Earth and the position of the people (2 m above the Earth's surface)

$C_{M}=\frac{m_{p}55(10)^{9} kg (6370998 m)}{5.9(10)^{24} kg+55(10)^{9} kg}$

$C_{M}=5.9(10)^{-8} m$ This is the displacement of Earth's center of mass from the original center.

8 0

2 years ago

A mechanic uses a mechanical lift to raise a car. The car weighs 11,000 N. The lift raises the car 2.5 m.

KengaRu [80]

Potential energy = (weight) x (height)

After the car has been raised 2.5 meters, it has

(11,000) x (2.5) = 27,500 Joules

MORE potential energy than it had before it was lifted.

That's the energy that has to come from the work you do to lift it.

Since no mechanical process is ever 100% efficient, the work required
to accomplish this task is <em>at least 27,500 joules</em>.

5 0

2 years ago

Read 2 more answers

What is the definition of differentiation geology?

UkoKoshka [18]

Any process in which a mixture of materials separates out partially

5 0

3 years ago