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2 years ago

Which shows one example of physical change and the one example of a chemical change?

Physics

1 answer:

atroni [7]2 years ago

8 0

Answer:

D. Freezing water and burning coal

Explanation:

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Explain the movement in the sky

Montano1993 [528]

The motion of planets is separate to the motion of stars. Like everything in the sky, they rise in the east, and set in the west, because of the earth's rotation. But night by night, their position at a given time changes because of their orbit around the sun.

7 0

2 years ago

Ammonia gas occupies a volume of 0.450 L at a pressure of 96 kPa. What

Sauron [17]

Answer:

0.426 L

Explanation:

Boyles law is expressed as p1v1=p2v2 where

P1 is first pressure, v1 is first volume

P2 is second pressure, v2 is second volume.

Given information

P1=96 kPa, v1=0.45 l

P2=101.3 kpa

Unknown is v2

Making v2 the subject from Boyle's law

$v2=\frac {p1v1}{p2}$

Substituting the given values then

$v2=\frac {96*0.45}{101.3}=0.4264560710760l\approx 0.426 l$

Therefore, the volume is approximately 0.426 L

6 0

2 years ago

If an object undergoes a change in momentum of 10 kg m/s in 3 s ,then the force acting on it is

Paha777 [63]

Answer:

Force = 3.333 Newton

Explanation:

Given the following data;

Change in momentum = 10 Kgm/s

Time = 3 seconds

To find the force acting on it;

In Physics, the change in momentum of a physical object is equal to the impulse experienced by the physical object.

Mathematically, it is given by the formula;

Force * time = mass * change in velocity

Impulse = force * time

Substituting into the formula, we have;

10 = force * 3

Force = 10/3

Force = 3.333 Newton

8 0

2 years ago

A sphere has a radius of 3.9cm and a density of 7.58 g/cm cubed. What is the mass?

snow_lady [41]

Answer:

m=ρV

V=4/3 * pi * r3

V=1.3 * 3.14 * 3.9^3

V=242.14 cm^3

m=7.58 * 242.14

m=1.8 kG

Explanation:

1. We calculate volume for sphere.

2. Then we calculate mass of sphere.

3 0

3 years ago

Write a balanced equation for the decomposition of ammonium nitrate to form molecular nitrogen, molecular oxygen, and water. Exp

VARVARA [1.3K]

The unbalanced reaction is

a NH₄NO₃ ⇒ b N₂ + c O₂ + d H₂O

where a, b, c, and d are unknown constants.

Count how many times each element appears on either side of the reaction.

• reactants:

N = 2a, H = 4a, O = 3a

• products

N = 2b, O = 2c + d, H = 2d

Now we solve the system of equations,

2a = 2b … … … [1]

4a = 2d … … … [2]

3a = 2c + d … … … [3]

From [1] we immediately have

a = b

In [2], we get

2a = d

and substituting for d in [3] gives

3a = 2c + 2a

a = 2c

Let c = 1; then

• a = 2×1 = 2

• b = 2

• d = 2×2 = 4

So, the balanced reaction is

2 NH₄NO₃ ⇒ 2 N₂ + O₂ + 4 H₂O

8 0

2 years ago