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rewona [7]
3 years ago
9

A type of invisible matter whose gravity affects how galaxies move is called _____. A. dim matter B. dark matter C. black dwarfs

D. white dwarfs
Physics
1 answer:
mr_godi [17]3 years ago
5 0

Answer:

B

Explanation:

The answer is B

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You toss a ball into the air and note the time interval between the ball leaving your hand and reaching its highest position. Wh
lawyer [7]

Answer:

It is longer

Explanation:

According to the theory of special relativity, moving clocks run slower. So, the construction worker moving at a constant speed observers a time much longer than the time I observe since I am stationary. If t is the time observed by me and v is the speed of the construction worker, then, the time observed by the construction worker, t' is given by

t' = t/√[1 - (v/c)²] where c = speed of light

So, the construction worker reports a longer time interval than me since his time runs slower.

8 0
3 years ago
What does friction oppose
Mekhanik [1.2K]

Answer:

Friction opposes motion.

Explanation:

If there is relative motion, the frictional force is the kinetic force of friction.

7 0
3 years ago
What affect does friction have on motion
satela [25.4K]

Answer: friction reduces the speed during motion

Explanation:

The more the friction, the lesser the speed during motion

3 0
4 years ago
A hollow plastic sphere is held below the surface of a fresh-water lake by a cord anchored to the bottom of the lake. The sphere
Naya [18.7K]

Answer: a) B = 6811N

              b) m = 603.2kg

              c) 86.8%

Explanation: <em>Buoyant force</em> is a force a fluid exerts on a submerged object.

It can be calculated as:

B=\rho_{fluid}.V_{obj}.g

where:

\rho_{fluid} is density of the fluid the object is in;

V_{obj} is volume of the object;

g is acceleration due to gravity, is constant and equals 9.8m/s²

a) For the hollow plastic sphere, density of water is 1000kg/m³:

B=10^{3}.0.695.9.8

B = 6811N

b) Anchored to the bottom, the forces acting on the sphere are <u>Buoyant</u>, <u>Tension</u> and <u>Force due to gravity</u>:

B = T + F_{g}

B = T + mg

mg = B - T

m=\frac{B - T}{g}

Calculating:

m=\frac{6811 - 900}{9.8}

m = 603.2kg

c) When the shpere comes to rest on the surface of the water, there are only <u>buoyant</u> <u>and</u> <u>gravity</u> acting on it:

B = m.g

\rho_{w}.V_{sub}.g=m.g

V_{sub}=\frac{m}{\rho_{w}}

V_{sub}=\frac{603.2}{1000}

V_{sub} = 0.6032m³

Fraction of the submerged volume is:

\frac{V_{sub}}{V_{obj}} = \frac{0.6932}{0.695} = 0.868

<u />

3 0
3 years ago
According to the diagram, which color of visible light has the shortest wavelength?
Fynjy0 [20]

Answer:

Violet Light

Explanation:

On one end of the spectrum is red light, with the longest wavelength. Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum. It has all the colors of the rainbow.

6 0
3 years ago
Read 2 more answers
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