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3 years ago

What is black matter?

1 answer:

5 0

I think you meant what is "Dark matter" if so the answer is Dark matter is a hypothetical form of matter that is thought to account for approximately 85% of the matter in the universe.

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A beam of unpolarized light with intensity I0 falls first upon a polarizer with transmission axis θTA,1 then upon a second polar

loris [4]

Answer:

The intensity I₂ of the light beam emerging from the second polarizer is zero.

Explanation:

Given:

Intensity of first polarizer = Io/2

For the second polarizer, the intensity is equal:

$I_{2} =\frac{I_{o} }{2} (cos\theta )^{2} =\frac{I_{o} }{2} (cos90)^{2} =0$

5 0

4 years ago

A 5.00-kg ball is hanging from a long but very light flexible wire when it is struck by a 1.50-kg stone traveling horizontally t

devlian [24]

consider the right direction as positive and left direction as negative.

M = mass of the ball = 5 kg

m = mass of stone = 1.50 kg

$V_{bi}$ = initial velocity of the ball before collision = 0 m/s

$V_{si}$ = initial velocity of the stone before collision = 12 m/s

$V_{bf}$ = final velocity of the ball after collision = ?

$V_{sf}$ = final velocity of the stone after collision = - 8.50 m/s

using conservation of momentum

M $V_{bi}$ + m $V_{si}$ = M $V_{bf}$ + m $V_{sf}$

(5) (0) + (1.5) (12) = 5 $V_{bf}$ + (1.50) (- 8.50)

$V_{bf}$ = 6.15 m/s

h = height gained by the ball

using conservation of energy

Potential energy gained by ball at Top = kinetic energy at the bottom

Mgh = (0.5) M $V_{bf}^{2}$

(9.8) h = (0.5) (6.15)²

h = 1.93 m

8 0

3 years ago

Read 2 more answers

A 0.50 kg mass is attached to a string 1.0 meter long and moves in a horizontal circle at a rate of 0.5 seconds per revolution.

vesna_86 [32]

(1) First compute the linear speed of the mass. If it completes 1 revolution in 0.5 seconds, then the mass traverses a distance of 2π (1.0 m) ≈ 2π m (the circumference of the circular path), so that its speed is

v = (1/0.5 rev/s) • (2π m/rev) = 4π m/s ≈ 12.57 m/s

Then the centripetal acceleration a is

a = v² / (1.0 m) = 16π² m/s² ≈ 160 m/s²

(where r is the path's radius).

(2) By Newton's second law, the tension in the string is T such that

T = (0.50 kg) a = 8π² N ≈ 79 N

7 0

3 years ago

When a physical change in a sample occurs, which of the following would NOT change?

GREYUIT [131]

It's Composition. (C)

3 0

3 years ago

The young tree was bent and has been brought into a vertical position by the three guy cables. If tension at AB = 0, AC = 10 lb,

KATRIN_1 [288]

Answer:

The young tree, originally bent, has been brought into the vertical position by adjusting the three guy-wire tensions to AB = 7 lb, AC = 8 lb, and AD = 10 lb. Determine the force and moment reactions at the trunk base point O. Neglect the weight of the tree.

C and D are 3.1' from the y axis B and C are 5.4' away from the x axis and A has a height of 5.2'

Explanation:

See attached picture.

3 0

4 years ago