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3 years ago

Which of the following statements about dark matter and dark energy is/are true?

Physics

1 answer:

REY [17]3 years ago

6 0

Answer:

A. Both exceed the matter-energy equivalent of luminous matter.

B. Dark matter has only an attractive gravitational effect, while dark energy is repulsive.

Explanation:

Dark matter and dark energy together constitute about ninety-five percent of the of total matter-energy equivalence in the universe. So, they exceed the matter-energy equivalent of luminous matter.

Dark energy is the repulsive force that is accelerating the expansion of the universe. Dark matter only has an attractive gravitational effect but does not interact with light of any kind.

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Power is the rate at which...........is done or the rate at which........... is converted from one form to another .

34kurt

Answer:

the answer is c I thought

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3 years ago

Which statement is correct? (2 points)

Lemur [1.5K]

Answer:

When a neutral atom looses an electron to another neutral atom, two charged atoms are created.

Explanation:

On the off chance that one of the two unbiased particle looses an electron, it turns out to be emphatically (charge: +1), in light of the fact that the electron conveys a charge of - 1. Thus, the other atom which acknowledges the electron turns out to be adversely charged (charge: - 1). And in the end, we will have two charged atoms.

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3 years ago

A 0.40 kg object is attached to a spring with force constant 157 N/m so that the object is allowed to move on a horizontal frict

nirvana33 [79]

Answer:

Part a)

$F = 26.7 N$

Part b)

$a = 66.7 m/s^2$

Explanation:

Part a)

Force on the object due to spring force is given as

$F = kx$

here we know that

$k = 157 N/m$

$x = 0.17 m$

so we have

$F = 157\times 0.17$

$F = 26.7 N$

Part b)

Acceleration of the object is given as

$a = \frac{F}{m}$

$a = \frac{26.7}{0.40}$

$a = 66.7 m/s^2$

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3 years ago

A ball whose mass is 0.4 kg hits the floor with a speed of 8 m/s and rebounds upward with a speed of 6 m/s. Collapse question pa

Colt1911 [192]

Answer:

The the average magnitude of the force exerted on the ball by the floor $11.2 \times 10^{3}$ N

Explanation:

Given:

Mass of ball $m = 0.4$ kg

Initial speed $v_{i} = -8 \frac{m}{s}$

Rebound speed $v_{f} = 6 \frac{m}{s}$

Contact time interval $\Delta t = 0.5 \times 10^{-3}$ sec

For finding the average magnitude of the force on the ball by the floor is given by,

$F_{avg} = \frac{\Delta P}{\Delta t}$

Here $\Delta P = m (v_{f}- v_{i} )$

$F_{avg} = \frac{m (v_{f} -v_{i} )}{\Delta t}$

$F_{avg} = \frac{0.4 \times (6 -( -8 ) )}{0.5 \times 10^{-3} }$

$F_{avg} = 11.2 \times 10^{3}$ N

Therefore, the the average magnitude of the force exerted on the ball by the floor $11.2 \times 10^{3}$ N

6 0

3 years ago

Read 2 more answers

Why empty tin-cans ocillating for a longer time

Natalija [7]

Answer: When you speak into the can, your voice creates air vibrations that travel into the can, vibrate the bottom of the can, which in turn vibrates the string all the way over to the other can, in turn vibrating the other can's bottom, then the air again.

Explanation:

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3 years ago