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
Makovka662 [10]
3 years ago
9

Name and explain two sleeping disorders

Physics
1 answer:
vfiekz [6]3 years ago
4 0
Insomnia and night terrors
You might be interested in
Question 14 Unsaved
defon

The correct answer is I disagree. Elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds.

Elements are pure substances but these elements also make other things such as water. The water molecule is made of two elements called oxygen and Hydrogen. Now water itself is a pure substance as it is chemically bonded hydrogen and Oxygen but it is composed of more than one element

3 0
4 years ago
If a projectile is launched vertically from the Earth with a speed equal to the escape speed, how high above the earth's surface
Alecsey [184]

Answer: h = 3R

Explanation:

Using the law of conservation of energy,

Total energy at the beginning of the launch would be equal to total energy at any point.

kinetic energy + gravitational potential energy = constant

Initial energy of the projectile =\frac{1}{2}mv_e^2-\frac{GMm}{R}... (1)

where R is the radius of the Earth, M is the mass ofthe Earth, m is the mass of the projectile.

escape velocity, v_e=\sqrt{\frac{2GM}{R}}

Total energy at height h above the Earth where speed of the projectile is half the escape velocity:

\frac{1}{2}m(v_e/2)^2-G\frac{Mm}{R+h} ...(2)

(1)=(2)

⇒\frac{1}{2}m(v_e/2)^2-G\frac{Mm}{R+h} = \frac{1}{2}mv_e^2-\frac{GMm}{R}

⇒G\frac{Mm}{R}-G\frac{Mm}{R+h}= \frac{1}{2}m \frac{3}{4}v_e^2 =\frac{1}{2}m \frac{3}{4} (\sqrt{\frac{2GM}{R}})^2

⇒\frac{GM(R+h-R)}{R(R+h)} = \frac{3}{4}(\frac{GM}{R})

⇒\frac{h}{R+h} = \frac{3}{4}

⇒h = 3R

Thus, at height equal to thrice radius of Earth, the speed of the projectile would reduce to half of escape velocity.  

4 0
3 years ago
Read 2 more answers
Acceleration is the change in distance over time. true or false
olganol [36]
the answer is true acceleration is the change in distance over time.
 hope this helps
7 0
3 years ago
Which acids are found in acid precipitation?
lapo4ka [179]

understand friend

hiiiiiiiiiiiiiiiiiiii

8 0
3 years ago
A scientist studies the effect of adding different amounts of salt on the boiling point of water. He places his results in the g
den301095 [7]
The amounts are the independent boiling water is dependent

5 0
3 years ago
Read 2 more answers
Other questions:
  • What is the current in the circuit if the charge passing each point is 240C in 5mins ?​
    13·1 answer
  • In a circuit a battery is used to
    14·2 answers
  • Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was
    13·1 answer
  • An 80.0-kg object is falling and experiences a drag force due to air resistance. The magnitude of this drag force depends on its
    5·1 answer
  • a 60 kg child sits on on the outer edge a playground merry-go-around with radius of 4 meters that spins around at 1 revolution e
    11·1 answer
  • An electric drill starts from rest and undergoes uniform angular acceleration for a period of 0.145 s until it turns at a rate o
    10·1 answer
  • What is the effect on climate from these factors??
    15·1 answer
  • Plz help it’s passed due!
    10·1 answer
  • What did the protoplanets become?
    5·2 answers
  • Which of these stars has the hottest core? (a) a white main-sequence star (b) an orange main-sequence star (c) a red main-sequen
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!