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
suter [353]
3 years ago
14

Samuel tripped while playing basketball and skinned his knee on the concrete. Many of the skin cells on that knee were killed or

removed entirely, leaving his knee open and unprotected. Eventually, his knee scabbed over, and when the scabs fell off, there was new skin underneath. Where did the new skin come from? A. Extra skin cells from other parts of Samuel's body were moved to the injury. B. Existing skin cells near the injury reproduced to make new cells. C. Skin cells near the injury increased in size to cover the injury. D. Existing cells near the injury changed into skin cells to cover the injury.
Physics
1 answer:
kvv77 [185]3 years ago
3 0
The answer is B. Old cells need to create new cells to replenish the ones that were lost.
You might be interested in
3. An object of mass 90 kg travels down a slide.
Gwar [14]

Answer:

3) Ep = 13243.5[J]

4) v = 17.15 [m/s]

Explanation:

3) In order to solve this problem, we must use the principle of energy conservation. That is, the energy will be transformed from potential energy to kinetic energy. We can calculate the potential energy with the mass and height data, as shown below.

m = mass = 90 [kg]

h = elevation = 15 [m]

Potential energy is defined as the product of mass by gravity by height.

E_{p}=m*g*h\\E_{p}=90*9.81*15\\E_{p}=13243.5[J]

This energy will be transformed into kinetic energy.

Ek = 13243.5 [J]

4) The velocity can be determined by defining the kinetic energy, as shown below.

E_{k}=\frac{1}{2} *m*v^{2}  \\v = \sqrt{\frac{2*E_{k} }{m} }\\ v= \sqrt{\frac{2*13243.5 }{90} }\\v=17.15[m/s]

4 0
3 years ago
The magnetic field in a cyclotron is 1.25 T, and the maximum orbital radius of the circulating protons is 0.40 m. (a) What is th
Darya [45]

Answer:

1.92 x 10⁻¹²J

Explanation:

The magnetic force from the magnetic field gives the circulating protons gives the particle the necessary centripetal acceleration to keep it orbiting round the circular path. And from Newton's second law of motion, the force(F) is equal to the product of the mass(m) of the proton and the centripetal acceleration(a). i.e

F = ma

Where;

a = \frac{v^2}{r}             [v = linear velocity, r = radius of circular path]

=> F = m\frac{v^2}{r}           ------------(i)

We also know that the magnitude of this magnetic force experienced by the moving charge (proton) in a magnetic field is given by;

F = q v B sin θ       ----------(ii)

Where;

q = charge of the particle

v = velocity of the particle

B = magnetic field

θ = the angle between the velocity and the magnetic field.

Combining equations (i) and (ii) gives

m\frac{v^2}{r} = q v B sin θ           [θ = 90° since the proton is orbiting at the maximum orbital radius]

=> m\frac{v^2}{r} = q v B sin 90°

=> m\frac{v^2}{r} = q v B

Divide both side by v;

=> m\frac{v}{r} = qB

Make v subject of the formula

v = \frac{qBr}{m}

From the question;

B = 1.25T

m = mass of proton = 1.67 x 10⁻²⁷kg

r = 0.40m

q = charge of a proton = 1.6 x 10⁻¹⁹C

Substitute these values into equation(iii) as follows;

v = \frac{(1.6*10^{-19})(1.25)(0.4)}{(1.67*10^{-27})}

v = 4.79 x 10⁷m/s

Now, the kinetic energy, K, is given by;

K = \frac{1}{2}mv²

m = mass of proton

v = velocity of the proton as calculated above

K = \frac{1}{2}(1.67*10^{-27} * (4.79 * 10^7)^2 )

K = 1.92 x 10⁻¹²J

The kinetic energy is 1.92 x 10⁻¹²J

8 0
3 years ago
50.0 meters away from a building. Tip of the building makes an angle of 63.0° with the horizontal. What is the height of the bui
soldi70 [24.7K]

Answer:

98.13m

Explanation:

Complete question

Daniel is 50.0 meters away from a building. Tip of the building makes an angle of 63.0° with the horizontal. What is the height of the building

CHECK THE ATTACHMENT

From the figure, using trigonometry

Tan(θ ) = opposite/adjacent

Where Angle (θ )= 63°

Opposite= X = height of the building

Adjacent= 50 m

Then substitute the values we have

Tan(63)= X/50

1.9626= X/50

X= 1.9626 × 50

X= 98.13m

Hence, the height of the building is 98.13m

8 0
2 years ago
An astronomer is observing a star which puzzles her. The lines in the star's spectrum indicates that the star is very hot and sh
Firlakuza [10]

Answer:

the stars which are red in color are cool.

Explanation:

The stars which has reddish color are cool in nature while those stars which has white and blue in color are very hot in nature. The stars change its color when they becomes hotter , first the star color reddish when they are cool but with increasing temperature it changes the color from reddish to orange then yellow. After yellow it turns green and finally get blue color when the stars are very very hot.

5 0
3 years ago
A 27 kg bear slides, from rest, 14 m down a lodgepole pine tree, moving with a speed of 6.1 m/s just before hitting the ground.
Nadusha1986 [10]
<h2>Thus the force of friction is 235 N</h2>

Explanation:

When the bear was at the height of 14 m . Its potential energy = m g h

here m is the mass of bear , g is acceleration due to gravity and h is the height .

Thus P.E =  27 x 10 x 14 = 3780 J

The K.E of the bear just before hitting = \frac{1}{2} m v²

=   \frac{1}{2} x 27 x ( 6.1 )²  = 490 J

The force of friction f = P.E - K.E = 3290 J

Because the work done = Force x Distance

Thus frictional force = \frac{3290}{14} = 235 N

3 0
3 years ago
Other questions:
  • Stability is a term that means... 
    10·1 answer
  • Which one of the following weight management plans is the most effective
    14·2 answers
  • Carla uses a table tennis ball and a volleyball to represent two astronomical bodies based on their sizes. Which of the followin
    11·2 answers
  • What part of an atom is responsible for producing magnetic fields
    8·1 answer
  • What is a circuit,s resistance if 12v produces 2A of current ?
    13·1 answer
  • What is the radius of the event horizon for a black hole with a mass 7.5 times the mass of the sun? This distance is called the
    15·1 answer
  • A nuetral atom has no overall charge. Explain this in terms of its particles.
    10·1 answer
  • . A dog walks 14 m to the east and then 20 m back to the west. What is the distance? What is the displacement?​
    9·1 answer
  • QUESTION 5 When an instrument is sounded together with a turning fork of frequency 260Hz , 2 beats are heard. When the same inst
    7·1 answer
  • 5. Your friend claims that the Moon’s repeated orbit around Earth causes the cycle of the Moon’s phases.
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!