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3 years ago

Which two statements are true about a system?

2 answers:

6 0

The first choice i correct. The second is also correct as it should obey the Law of Conservation of mass. The third choice is incorrect. It depends on the nature of the system. For example, for an ideal gas, you can define at least 2 parameters to set the system boundaries. The fourth choice is incorrect, a system can be theoretical or practical. Hence, the answers are the first and second choices.

mylen [45]3 years ago

3 0

Answer:

1. A system is a group of objects analyzed as one unit.

2. Energy that moves across system boundaries is conserved.

Explanation:

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Why would a positive current flow from the positive end of a wire towards its negative end?

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because positive and negative attract

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3 years ago

What are some modern uses for infrasound example, ultrasound can be used in the medical field to look inside people. Thanks!

lyudmila [28]

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3 years ago

The energy of atoms and molecules in an object due to their motion is_______ energy

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3 years ago

Hey stob it. Please help me. Cmon help me. Plz.

Anna [14]

Answer:

3) D: 31 m/s

4) D: 84.84 metres

Explanation:

3) Initial velocity along the x-axis is;

v_x = v_o•cos θ

Initial velocity along the y-axis is;

v_y = v_o•sin θ

Plugging in the relevant values, we have;

v_x = 31 cos 60

v_x = 31 × 0.5

v_x = 15.5 m/s

Similarly,

v_y = 31 sin 60

v_y = 31 × 0.8660

v_y = 26.85 m/s

Thus, magnitude of the initial velocity is;

v = √(15.5² + 26.85²)

v ≈ 31 m/s

4) Formula for horizontal range is;

R = (v² sin 2θ)/g

R = (31² × sin (2 × 60))/9.81

R = 84.84 m

6 0

3 years ago

Using our understanding of the law of gravity. What happens to the gravity as we triple the distance between two objects?

MA_775_DIABLO [31]

Answer:

1/9

Explanation:

Newton’s Law of Universal Gravitation

Objects with mass feel an attractive force that is proportional to their masses and inversely proportional to the square of the distance.

F = GMm/r²

where

F - the gravitatioal force in Newtons,

M and m -two masses in kilograms

r - the separation in meters.

G - the gravitational constant (6.674*10 ⁻¹¹ N (m/kg) ² )

Because of the magnitude of G , gravitational force is very small unless large masses are involved.

So according to above equation , when the masses are not changing , force is inversely propotional to the square of distance

F1 ∝ 1/r² ---------------(1)

F2 ∝ 1(3r)²

F2 ∝ 1/9r²--------------(2)

(2)/(1)

$\frac{F_2}{F_1} =\frac{1}{9}\\ F_2 =\frac{F_1}{9}$

From their you get as the distance tripled, Force reduce by a factor of 9(3³)

for example , assume the distance get doubled ,Force reduce by a factor of 4 (2²)

3 0

3 years ago