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3 years ago

What is dark energy?

1 answer:

4 0

Dark energy is a theoretical repulsive energy that causes the acceleration to the expansion of the universe. Among the choices, the nearest answer would be D. Dark energy can also be defined as a new form of energy, that is a dynamic field that fills up space but has an effect opposite to that of normal energy.

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The magnetic field strength at the north pole of a 2.0-cmcm-diameter, 8-cmcm-long Alnico magnet is 0.10 TT. To produce the same

horrorfan [7]

Answer:

2653 turns

Explanation:

We are given that

Diameter,d=2 cm

Length of magnet,l=8 cm= $8\times 10^{-2} m$

1m=100 cm

Magnetic field,B=0.1 T

Current,I=2.4 A

We are given that

Magnetic field of solenoid and magnetic are same and size of both solenoid and magnetic are also same.

Length of solenoid= $8\times 10^{-2} m$

Magnetic field of solenoid

$B=\frac{\mu_0NI}{l}$

Using the formula

$0.1=\frac{4\pi\times 10^{-7}\times 2.4\times N}{8\times 10^{-2}}$

Where $\mu_0=4\pi\times 10^{-7}$

$N=\frac{0.1\times 8\times 10^{-2}}{4\pi\times 10^{-7}\times 2.4}=2653 turns$

6 0

3 years ago

A satellite system that has unique properties is the ____ satellite, which is used by governments for spying and by scientific a

agasfer [191]

Answer: Highly-elliptical-earth-orbit (heo)

Explanation: Highly-elliptical-earth-orbit (heo) satellite system has unique properties

which is used by governments for spying and by scientific agencies for observing celestial bodies. It is an extremely elongated orbit that is useful for communication satellites which creates signals between a source transmitter and a receiver at different locations on earth. They are used by government for spying, scientific agencies for observing celestial bodies, for the internet and telephone communications.

6 0

3 years ago

Read 2 more answers

19. State any 3 applications of capillary action (3mk)

zlopas [31]

Explanation:

1. Movement of water, food and mineral salts in plants

2. Absorption of water by towels when wiping our bodies

3. It is used to absorb ink using a blotting paper or tissue

7 0

3 years ago

If the coefficient of static friction is 0.357, and the same ladder makes a 58.0° angle with respect to the horizontal, how far

zavuch27 [327]

Answer: d= 0.57* l

Explanation:

We need to check that before ladder slips the length of ladder the painter can climb.

So we need to satisfy the equilibrium conditions.

So for ∑Fx=0, ∑Fy=0 and ∑M=0

We have,

At the base of ladder, two components N₁ acting vertical and f₁ acting horizontal

At the top of ladder, N₂ acting horizontal

And Between somewhere we have the weight of painter acting downward equal to= mg

So, we have N₁=mg

and also mg*d*cosФ= N₂*l*sin∅

So,

d= $\frac{N2}{mg}*l$ * tan∅

Also, we have f₁=N₂

As f₁= чN₁

So f₁= 0.357 * 69.1 * 9.8

f₁= 241.75

Putting in d equation, we have

d= $\frac{241.75}{69.1*9.8} *l$ * tan 58

d= 0.57* l

So painter can be along the 57% of length before the ladder begins to slip

3 0

3 years ago

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A balloon of diameter 20.0 cm is filled with helium gas at 30°C at 1.00 atm. How

bogdanovich [222]

Answer:

N = 3.54 * 10²³ atoms

Explanation:

The formula to apply here is the idea gas law;

PV = nRT where ;

P= pressure of the gas= 1.013 * 10⁵ Pa

V= volume of the gas = 4/3 * 3.14 *0.15³= 0.01414 m³

n= amount of a substance = ?

R= ideal gas constant= 8.314

T= temperature= 293 K

Applying the values to the formula;

PV = nRT

1.013 * 10⁵ * 0.01414 = n * 8.314*293

n= 1.013 * 10⁵ * 0.01414 / 8.314*293

n= 0.588 moles

1 mole = 6.022 * 10²⁷ atoms/ mole

0.588 moles = 0.588 * 6.022 * 10²⁷

N = 3.54 * 10²³ atoms

8 0

3 years ago