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3 years ago

What is the definition of chemical change

1 answer:

3 0

Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. These changes are chemical: iron rusting (iron oxide forms) gasoline burning (water vapor and carbon dioxide form)

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What is matter, atom, molecules?

bagirrra123 [75]

matter is a solid liquid or gas , a atom is a basic unit of a chemical element and a molecule is a group of atoms together

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3 years ago

A hose directs a horizontal jet of water, moving with a velocity of 20m/s, on to a vertical wall. The

just olya [345]

Force is defined as the rate of change of momentum.
The initial amount of momentum is $mv$ because water stops when it hit the wall total change of momentum must be $\Delta p=mv$ .
Now let's calculate the force.
$F= \frac{dp}{dt}=\frac{d(mv)}{dt}=\frac{dm}{dt}v$
We need to find $\frac{dm}{dt}$ . This is the amount of water hiting the wall per second.
$\frac{dm}{dt}=\rho Av$
Our final formula would be:
$F=\rho Avv=\rho Av^2$
And now we can calculate the answer:
$F=1000\cdot5\cdot 10^{-4}\cdot(20)^2=200 N$

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2 years ago

An electric charge, A, is placed carefully between two other charges, B and C, and experiences no net electric force. Do B

Brrunno [24]

Answer:

I do not have enough information to tell

Explanation:

This is deduced due to the fact that if the net force due to B and C on A is zero, the charges on B and C could either be positive or negative depending on the charge on A.

5 0

3 years ago

1 1.3.3 Test (CST): Marketing and

Angelina_Jolie [31]

I would have to say D

8 0

2 years ago

2. Two cars A and B are heading forward. The velocity of A and B are 30 m/s and 20 m/s

KengaRu [80]

Answer:

A.) 27000 kgm/s

18000 kgm/s

B.) Va = 22 m/s

C.) 19800 kgm/s

25200 kgm/s

Explanation: Given that the velocity of A and B are 30 m/s and 20 m/s. And of the same mass M = 9 × 10^5g

M = 9×10^5/1000 = 900 kg

A.) Initial momentum of A

Mu = 900 × 30 = 27000 kgm/s

Initial momentum of B

Mu = 900 × 20 = 18000 kgm/s

B.) if they have an accident and then the velocity of the B is 28 m/s, find out velocity of A.

Momentum before impact = momentum after impact

Given that Vb = 28 m/s

27000 + 18000 = 900Va + 900 × 28

45000 = 900Va + 25200

900Va = 45000 - 25200

900Va = 19800

Va = 19800/900

Va = 22 m/s

C.) Momentum of A after impact

MV = 900 × 22 = 19800 kgm/s

Momentum of B after impact

MV = 900 × 28 = 25200 kgm/s

8 0

3 years ago