1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ale4655 [162]
3 years ago
14

Is saliva breaking a down a piece of bread chemical or physical

Physics
2 answers:
Elza [17]3 years ago
8 0
It's a chemical change since it cannot be reversed and the saliva releases a new substance
Vlad1618 [11]3 years ago
5 0
Chemical because saliva has a acid type substance in it
You might be interested in
According to the Second Law of Thermodynamics, a. any process during which the entropy of the universe increases will be product
Iteru [2.4K]

Answer:

The correct option is;

a. Any process in which the entropy of the universe increases will be product-favored

Explanation:

According to the second law of thermodynamics, the change in entropy of a closed system with time is always positive. That is the entropy of the entire universe, considered as an isolated system, always increases with time, hence the entropy change in the universe will always be positive.

\Delta S_{universe} = \Delta S_{system}  + \Delta S_{surroundings} >0

Therefore, any process in which the entropy of the universe increases will be product favored.

4 0
3 years ago
An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84. At room temperature, this element is a very
Grace [21]

Answer:

12 neutrons

Explanation:

The number of protons also shows the atomic number. Therefore the element in question is Krypton (Kr), which also is a noble gas.

Neutrons = Mass number - protons - electrons

Here neutrons = 84 - 36 - 36 = 12

5 0
3 years ago
How long must a 400w electrical engine work in order to produce 300kj of work
vladimir1956 [14]

Answer:

300000 J / 400 J/s = 750 s = 12.5 minutes

Explanation:

8 0
2 years ago
A box having a mass of 0.2 kg is dragged across a horizontal floor by
Lyrx [107]

you can check attachment for answer.

kind regards

7 0
3 years ago
A hippo drives 42 km due East. He then turns and drives 28 km at 25° East of South. He turns again and drives 32 km at 40° North
ch4aika [34]

Answer:

a) Please, see the attched figure

b) Total displacement R = (78.3 km; -4.8 km)

c) R = (78.4 km * cos (-3.5°); 78.4 km * sin (-3.5°))

d) The hippo is 78.4 km from his starting point.

The total distance traveled is 102 km

Explanation:

a)Please, see the attached figure.

b) The vector A can be expressed as:

A = (magnitude * cos α; magnitude * sin α)

Where

magnitude = 42 km

α= 0

Then,

A = (42 km ; 0) or 42 km i

In the same way, we can proceed with the other vectors:

B = ( Bx ; By)

where

(apply trigonometry of right triangles: sen α = opposite / hypotenuse and

cos α = adjacent / hypotenuse. See the figure to determine which component of vector B is the opposite and adjacent side to α)

Bx = 28 km * sin 25 = 11.8 km

By = 28 km * cos 25 = -25.4 km (it has to be negative since it is directed towards the negative vertical region according to our reference system)

B = (11.8 km; -25.4 km) or 11.8 km i - 25.4 km j

C = (Cx; Cy)

where

Cx = 32 km * cos 40° = 24.5 km

Cy = 32 km * sin 40 = 20.6 km

C = (24.5 km; 20.6 km)

Then:

R = A+B+C = (42 km + 11.8 km + 24.5 km; 0 - 25.4 km + 20.6 km)

= (78.3 km; -4.8 km) or 78.3 km i -4.8 km j

c) R = (78.3 km; -4.8 km)

The magnitude of R is:

magnitude = \sqrt{(78.3)^{2 }+ (-4.8)^{2}}= 78.4 km

Using trigonometry, we can calculate the angle:

Knowing that

tan α = opposite / adjacent

and that

opposite = Ry = -4.8 km

adjacent = Rx = 78.3 km

Then:

tan α = -4.8 km / 78.4 km

α = -3.5°

We can now write the vector R in magnitude and direction form:

R = (78.4 km * cos (-3.5°); 78.4 km * sin (-3.5°))

d) The displacement of the hipo relative to the starting point is the magnitude of vector R calculated in c):

magnitude R = 78. 4 km

The total distance traveled is the sum of the magnitudes of each vector:

Total distance = 42 km + 28 km + 32 km = 102 km  

3 0
2 years ago
Other questions:
  • Which of the following is the best example of a compression force?
    6·2 answers
  • Suppose that the electric potential outside a living cell is higher than that inside the cell by 0.063 V. How much work is done
    13·1 answer
  • Which is it. I don't understand
    10·2 answers
  • Assume a comet is traveling at a constant velocity in deep space. Why would it speed up as it approaches our solar system?
    5·1 answer
  • Which of the following is the best definition of autoimmune disease?
    10·1 answer
  • 8) What kind of circulation carries blood to all organs and systems?
    14·2 answers
  • Pluto's atmosphere. As recently observed by the New Horizons mission, the surface pressure of Pluto is about 11 microbar. The su
    11·1 answer
  • If we took our laboratory spring to the moon, how accurately would it measure the mass? Why?
    7·1 answer
  • Hunters velocity was 4.5 m/s. At the end of his race, his velocity was the same. Which best describes his Movement?
    8·1 answer
  • A basketball player jumps straight up with a speed of 14 m/s. How high did the player jump?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!