Ask question

Ask question

All categories

1 year ago

5

How do you know that a chemical change has happened

2 answers:

Maurinko [17]1 year ago

7 0

A substance is there now that wasn't there before. (And you didn't put it there.,)

Elodia [21]1 year ago

6 0

Answer:

theres is many states of chemical change but its not exaclty the same as physical the appearence might change alittle but chemical like frying a egg is a chemical change because a change of materials into another, new materials with different properties and one or more than one new substances are formed and the subtance changeing or the materials can show chemical changed happened you cant always see it but touching too like heat energy can show a chemical change

Explanation:

i hope this helps and keep ur grades up :)

You might be interested in

What is the evidence proving that we're in the 6th mass extinction?

Sveta_85 [38]

Answer:

Global warming and climate change

8 0

2 years ago

A student standing on a stationary skateboard tosses a textbook with a mass of mb = 1.25 kg to a friend standing in front of him

juin [17]

Answer:

The velocity of the student has after throwing the book is 0.0345 m/s.

Explanation:

Given that,

Mass of book =1.25 kg

Combined mass = 112 kg

Velocity of book = 3.61 m/s

Angle = 31°

We need to calculate the magnitude of the velocity of the student has after throwing the book

Using conservation of momentum along horizontal direction

$m_{b}v_{b}\cos\theta= m_{c}v_{c}$

$v_{s}=\dfrac{m_{b}v_{b}\cos\theta}{m_{c}}$

Put the value into the formula

$v_{c}=\dfrac{1.25\times3.61\times\cos31}{112}$

$v_{c}=0.0345\ m/s$

Hence, The velocity of the student has after throwing the book is 0.0345 m/s.

3 0

2 years ago

A 65-kg ice skater stands facing a wall with his arms bent and then pushes away from the wall by straightening his arms. At the

Marrrta [24]

Our values can be defined like this,

$m = 65kg$

$v = 3.5m / s$

$d = 0.55m$

The problem can be solved for part A, through the Work Theorem that says the following,

$W = \Delta KE$

Where

KE = Kinetic energy,

Given things like that and replacing we have that the work is given by

W = Fd

and kinetic energy by

$\frac {1} {2} mv ^ 2$

So,

$Fd = \frac {1} {2} m ^ 2$

Clearing F,

$F = \frac {mv ^ 2} {2d}$

Replacing the values

$F = \frac {(65) (3.5)} {2 * 0.55}$

$F = 723.9N$

B) The work done by the wall is zero since there was no displacement of the wall, that is d = 0.

6 0

2 years ago

What two characteristics are used to classify air masses

IgorLugansk [536]

Answer: Temperature and humidity are the two characteristics used to classify air masses.

Explanation:

7 0

2 years ago

Which of these nebulae is the odd one out?

Lubov Fominskaja [6]

Answer: The answer is D!

Explanation:

5 0

2 years ago

Read 2 more answers