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
Vedmedyk [2.9K]
3 years ago
8

1 The Earth's crust is made up of plates that can move. Which of the following topographic features could be directly formed by

the movement of the Earth's plates? I. midocean ridges II. mountains III. sand dunes IV. coral reefs A. I, II, and III only B. II, III, and IV only C. I and II only D. II and III only
Physics
1 answer:
olga_2 [115]3 years ago
7 0
Can you write this better and from my info of what i know i know that one way is the trenches in the ocean like marianas trench  <span />
You might be interested in
Traumatic brain injury such as a concussion results when the head undergoes a very large acceleration. Generally an acceleration
eimsori [14]

The complete text of the problem is:

<em>"Traumatic brain injury such as concussion results when the head undergoes a very large acceleration. Generally, an acceleration less than 800 m/s2 lasting for any length of time will not cause injury, whereas an acceleration greater than 1000 m/s2 lasting for at least 1 ms will cause injury. Suppose a small child rolls off a bed that is 0.43 m above the floor. If the floor is hardwood, the child's head is brought to rest in approximately 1.8 mm. If the floor is carpeted, this stopping distance is increased to about 1.1 cm. Calculate the magnitude and duration of the deceleration in both cases, to determine the risk of injury. Assume the child remains horizontal during the fall to the floor. Note that a more complicated fall could result in a head velocity greater or less than the speed you calculate. "</em>

<em />

<u>Solution:</u>

1) Acceleration: -2336 m/s^2 on the hardwood floor, -382 m/s^2 on the carpeted floor

First of all, we need to calculate the speed of the child just before he hits the floor. This can be done by using the equation

v^2 - u^2 = 2ad

where

v is the final speed

u = 0 is the initial speed (the child starts from rest)

a = g = 9.8 m/s^2 is the acceleration of gravity

d = 0.43 m is the distance covered by the child as he falls from the bed

Solving for v,

v=\sqrt{2ad}=\sqrt{2(9.8)(0.43)}=2.9 m/s

Now we can analyze the moment of the collision. The child hits the floor with an initial speed of v = 2.9 m/s, and he comes to a stop, so the final speed is v' = 0. If the floor is hardwood, the stopping distance is

d = 1.8 mm = 0.0018 m

So we can find the acceleration by using again the equation

v'^2 - v^2 = 2ad

Solving for a,

a=\frac{v'^2 - v^2}{2d}=\frac{0-2.9^2}{2(0.0018)}=-2336 m/s^2

For the carpeted floor instead,

d=1.1 cm = 0.011 m

therefore the acceleration is

a=\frac{v'^2 - v^2}{2d}=\frac{0-2.9^2}{2(0.011)}=-382 m/s^2

2) Duration: 1.24 ms for the hardwood floor, 7.59 ms for the carpeted floor

We can find the duration of the collision in both cases by using the equation of the acceleration

a=\frac{v'-v}{t}

where

v' = 0

v = 2.9 m/s

For the hardwood floor,

a=-2336 m/s^2

So the duration of the collision is

t = \frac{v'-v}{a}=\frac{0-2.9}{-2336}=0.00124 s = 1.24 ms

For the carpeted floor,

a=-382 m/s^2

So the duration of the collision is

t = \frac{v'-v}{a}=\frac{0-2.9}{-382}=0.00759 s = 7.59 ms

We can now comment the results using the initial statement of the problem:

"Generally an acceleration less than 800 m/s2 lasting for any length of time will not cause injury, whereas an acceleration greater than 1,000 m/s2 lasting for at least 1ms will cause injury"

Therefore, the fall on the hardwood floor can result in injury (since the acceleration is greater than 1,000 m/s2 for more than 1 ms), while the fall on the carpeted floor is not dangerous (much less than 1000 m/s^2).

8 0
3 years ago
How dose an atom change if all of its electrons are removed
cluponka [151]

Answer:

The atom becomes a positively charged ion.

Explanation:

  1. The building blocks of an atom are protons, neutrons, and electrons.
  2. The protons and neutrons present in the core of the atom are called nucleus.
  3. The electrons are scattered in an ordered way around the nucleus.
  4. The protons are positively charged and the electrons are negatively charged particles. The neutrons do not possess any charges.
  5. Binding energy is supplied to the atom to remove an electron.
  6. It is possible to remove the electrons of the lighter elements.
  7. When an electron is removed from the hydrogen atom. It becomes positively charged ion or simply proton.
  8. When all of the electrons are removed from the helium atom, it becomes a positively charged α particle.
  9. It is practically very difficult to remove all of the electrons from the heavier elements.
  10. When all of the electrons are removed from an atom it becomes an unstable positively charged ion.
7 0
3 years ago
A dragster starts with zero velocity and completes a 404.5 m (0.2528 mile) run in 4.922 s. If the car had a constant acceleratio
KIM [24]

Answer:

a. a=33.34ms⁻², V=164.4m/s

Explanation:

Since the dragster started with zero velocity, de determine the acceleration using of the equations of motion.

Below are the data given

Distance, s=404.5m,

time taken,t=4.922secs

Using the equation

S=ut+1/2at²

where u is the initial velocity and u=0

Making the acceleration the subject of the formula, we arrive at

a=2s/t²

a=(2*404.5)/4.922²

a=33.34ms⁻².

To determine the velocity, we use

V=u+at

V=0+33.34ms⁻² *4.922sec

V=164.4m/s

5 0
3 years ago
Read 2 more answers
Please answer this. Science 7th grade.
nikdorinn [45]

Answer:

the answer would be 2

Explanation:

it would be 2 because if u look at the diagram the darkest arrow is pointsin towards earth and the moon and when the moon is infront of the sun it cause's an eclispe

6 0
3 years ago
Coherent light that contains two wavelengths, 660 nm and 470 nm , passes through two narrow slits with a separation of 0.280 mm
bekas [8.4K]

Answer:

λ1 = 0.0129m = 1.29cm

λ2 = 0.00923m = 0.92 cm

Explanation:

To find the distance between the first order bright fringe and the central peak, can be calculated by using the following formula:

y_m=\frac{m\lambda D}{d}    (1)

m: order of the bright fringe = 1

λ: wavelength of the light = 660 nm, 470 nm

D: distance from the screen = 5.50 m

d: distance between slits = 0.280mm = 0.280 *10^⁻3 m

ym: height of the m-th fringe

You replace the values of the variables in the equation (1) for each wavelength:

For λ = 660 nm = 660*10^-9 m

y_1=\frac{(1)(660*10^{-9}m)(5.50m)}{0.280*10^{-3}m}=0.0129m=1.29cm

For λ = 470 nm = 470*10^-9 m

y_1=\frac{(1)(470*10^{-9}m)(5.50m)}{0.280*10^{-3}m}=0.00923m=0.92cm

7 0
3 years ago
Other questions:
  • Why does a lead of a pencil becomes smaller after use brainly people plplplsss help
    7·1 answer
  • true/false: a single atom of an element in molecular and empirical formulas does not require a subscript
    9·1 answer
  • An airplane is traveling 25° west of north at 300 m/s when a wind with velocity 100 m/s directed 35° east of north begins to blo
    15·1 answer
  • What would the world be like without energy?
    15·1 answer
  • Can someone please help me!
    5·1 answer
  • Three thermometers are in the same water bath. After thermal equilibrium is established, it is found that the Celsius thermomete
    9·1 answer
  • Name the first Reserve Forest of India.<br><br><br> Pls tell this ans
    8·1 answer
  • Un carro parte del reposo y acelera uniformemente a 4.0 m / s^2 durante 5.0 s. A continuación, mantiene la velocidad que alcanzó
    14·1 answer
  • PLEASE ANSWER NEED HELP!!!!!!!! PLEASE THE CORRECT ANSWER!!!!!!
    15·2 answers
  • Echoic sensory memory is used when a lightning bolt flashes across the sky. please select the best answer from the choices provi
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!