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3 years ago

Please Help Me!!!

Physics

2 answers:

Roman55 [17]3 years ago

4 0

Answer:Its D

Explanation:

Because im not an idiot, i think.

OLEGan [10]3 years ago

3 0

Answer: C

Explanation: Polar molecules differ from nonpolar molecules by having positive and negative ends and stronger intermolecular forces of attraction Nonpolar molecules have only weak attractive forces for each other, so nonpolar substances tend to have low melting points and boiling points

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The sun is 150,000,000 km from the earth.

aniked [119]

Answer:

<h3>What is the angular speed of the earth around the sun? </h3>

It takes the Earth approximately 23 hours, 56 minutes and 4.09 seconds to make one complete revolution (360 degrees). This length of time is known as a sidereal day. The Earth rotates at a moderate angular velocity of

$7.2921159 × 10 {}^{ - 5} \: \: \frac{radians}{second}$

<h3>What is the tangential speed of the earth? </h3>

The earth rotates once every 23 hours, 56 minutes and 4.09053 seconds, called the sidereal period, and its circumference is roughly 40,075 kilometers. Thus, the surface of the earth at the equator moves at a speed of 460 meters per second--or roughly 1,000 miles per hour.

8 0

3 years ago

What kind of lens is there in our eyes? where does it form the image of an object?

Goshia [24]

Answer:

convex lens

Explanation:

An image is form in retina with light rays converging most at cornea and upon entering and existing the lens.Rays from top and bottom of the object are traced and produce an inverted image on the retina

8 0

2 years ago

A wire of Nichrome (a nickelâ€“ chromiumâ€“ iron alloy commonly used in heating elements) is 1.0 m long and 1.0 mmÂ² in cross-se

Lyrx [107]

Answer:

The conductivity of Nichrome is $2\times 10^6\ S/m$ .

Explanation:

Given:

Potential difference (V) = 2.0 V

Current flowing (I) = 4.0 A

Length of wire (L) = 1.0 m

Area of cross section of wire (A) = 1.0 mm² = 1 × 10⁻⁶ m² [1 mm² = 10⁻⁶ m²]

We know, from Ohm's law, that the ratio of voltage and current is always a constant and equal to the resistance of the resistor. Therefore, the resistance of the nichrome wire is given as:

$R=\frac{V}{A}=\frac{2.0}{4.0}=0.5\ \Omega$

Now, resistance of the nichrome wire in terms of its resistivity, length and area of cross section is given as:

$R=\rho\frac{L}{A}$

Where, $\rho\to resistivity\ of\ Nichrome$

Now, plug in all the values given and solve for $\rho$ . This gives,

$0.5\ \Omega=\rho\frac{1.0\ m}{1\times 10^{-6}\ m^2}\\\\\rho=\frac{0.5\times 1\times 10^{-6}}{1.0}=0.5\times 10^{-6}\ \Omega-m$

Now, conductivity of a material is the reciprocal of its resistivity. Therefore, the conductivity of Nichrome is given as:

$\sigma=\frac{1}{\rho}=\frac{1}{0.5\times 10^{-6}}=2\times 10^6\ S/m$

Conductivity is measured in Siemens per meter (S/m)

Therefore, the conductivity of Nichrome is $2\times 10^6\ S/m$ .

7 0

2 years ago

a hot pot of water is set on the counter to cool. after a few minutes it has lost 755 j of heat energy. how much heat energy has

velikii [3]

The heat energy the surrounding air gained is <u>755 j.</u>

Energy is a quantitative property given to a body or physical system and can be identified as work being done in the form of heat and light. Energy is Conserved - The law of conservation of energy states that energy can be transformed into form, but cannot be created or destroyed. Energy is the ability to do work. It can exist in electrical, kinetic, thermal, electrical, chemical, nuclear, or other forms.

<u>Concept:-</u>

Since the energy is always conserved, the energy lost by the hot water is gained bt the surrounding

- energy lost = + energy gained by the surrounding

- 755 j = + <u>755 j</u>

<u />

Energy exists in many forms. Examples include light energy, thermal energy, mechanical energy, gravitational energy, electrical energy, acoustic energy, chemical energy, and nuclear or atomic energy. Each form can be transformed or changed into other forms.

Learn more about energy here:-brainly.com/question/13881533

#SPJ1

5 0

9 months ago

5–111. A box having a weight of 8 lb is moving around in a circle of radius rA = 2 ft with a speed of (vA)1 = 5 ft>s while co

Elis [28]

Answer:

a) vB = 10.77 ft/s

b) W = 11.30 lb*ft

Explanation:

a) W = 8 lb ⇒ m = W/g = 8 lb/32.2 ft/s² = 0.2484 slug

vA <em>lin</em> = 5 ft/s

rA = 2 ft

v <em>rad</em> = 4 ft/s

vB = ?

rB = 1 ft

W = ?

We can apply The law of conservation of angular momentum

L<em>in</em> = L<em>fin</em>

m*vA*rA = m*vB*rB ⇒ vB = vA*rA / rB

⇒ vB = (5 ft/s)*(2 ft) / (1 ft) = 10 ft/s (tangential speed)

then we get

vB = √(vB tang² + vB rad²) ⇒ vB = √((10 ft/s)² + (4 ft/s)²)

⇒ vB = 10.77 ft/s

b) W = ΔK = K<em>B</em> - K<em>A</em> = 0.5*m*vB² - 0.5*m*vA²

⇒ W = 0.5*m*(vB² - vA²) = 0.5*0.2484 slug*((10.77 ft/s)²-(5 ft/s)²)

⇒ W = 11.30 lb*ft

6 0

3 years ago