answer.
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
Gwar [14]
2 years ago
10

When the volcano Krakatoa erupted in 1883, it was heard 5000 km away. Which statement about the sound from the volcano is not co

rrect?
a. If such a loud sound were to be made today, an astronaut orbiting in space (a vacuum) at a height of 400 km could hear it.
b. People further from the volcano heard the sound later than people nearer to the volcano.
c. The amplitude of the sound waves would have been smaller further from the volcano.
d. The sound was very loud because a lot of energy was transferred to vibrations of the air.
Physics
1 answer:
lina2011 [118]2 years ago
7 0
Answer a) is incorrect as sound does not travel in a vacuum.
You might be interested in
You are wallpapering two walls of a room. One wall measures 15 ft by 12 ft and the other measures 9 ft by 12 ft. The wall paper
enyata [817]

Answer:

5.76 round off to 6

Explanation:

wall 1 = 15 × 12 = 180

wall 2 = 9 × 12 = 108

now 1 roll covers 50 square feet

formula = wall 1 + wall 2 / 50

= 180 + 108 / 50

= 288÷ 50

= 5.76

4 0
2 years ago
According to the article, which pattern of brain waves are most conducive to studying new information?
sashaice [31]
Alpha brain waves are those most conducive to studying new information.

When consciously alert, we generally function along a beta brain rhythm. In diminishing this rhythm to alpha, we transition into a state of physical and mental relaxation that is ideal for learning new information and storing facts and  data. Studies have shown that the effect of decreasing brain rhythm is linked to feelings of increased mental clarity and remembrance. As it is a prime condition for synthetic thought and creativity, it becomes easier to visualize and create associations (information is better learned and absorbed by using such study methods). 

Hope this helps! :)
7 0
2 years ago
Eratosthenes determined the circumference of Earth by conducting an experiment. Put his steps in order as they correlate to the
galben [10]

Solution: The correct order is: C, A, B

The statement of the problem:

How can we prove Earth is round and calculate its circumference?

Hypotheis:

If the sun casts shadows at different angles at the same time of day in different places, we can determine how much Earth curves.

If the Earth was flat, the angle measured at different places at the same time of the day would be same.

Observation:

In Syene, the sun's rays are vertical at noon. At the same time in Alexandria, the rays are 7.2 degrees from the vertical.

5 0
2 years ago
A woman fires a rifle with barrel length of 0.5400 m. Let (0, 0) be where the 125 g bullet begins to move, and the bullet travel
dybincka [34]

Answer:

Explanation:

Given that,

Length of barrel =0.54m

Mass of bullet=125g=0.125kg

Force extend

F=16,000+10,000x-26,000x²

a. Work done is given as

W= ∫Fdx

W= ∫(16,000+10,000x-26,000x² dx from x=0 to x=0.54m

W=16,000x+10,000x²/2 -26,000x³/3 from x=0 to x=0.54m

W=16,000x+5,000x²- 8666.667x³ from x=0 to x=0.54m

W= 16,000(0.54) + 5000(0.54²) - 8666.667(0.54³) +0+0-0

W=8640+1458-1364.69

W=8733.31J

The workdone by the gas on the bullet is 8733.31J

b. Work done is given as

Work done when the length=1.05m

W= ∫Fdx

W= ∫(16,000+10,000x-26,000x² dx from x=0 to x=1.05m

W=16,000x+10,000x²/2 -26,000x³/3 from x=0 to x=1.05m

W=16,000x+5,000x²- 8666.667x³ from x=0 to x=1.05mm

W= 16,000(1.05) + 5000(1.05²) - 8666.667(1.05³) +0+0-0

W=16800+5512.5-10032.75

W=12,279.75J

The workdone by the gas on the bullet is 12,279.75J

3 0
2 years ago
Lilli suggests that they explore the simulation starting with varying only a single parameter in order to understand the role of
mrs_skeptik [129]

Answer:

B.

Explanation:

One of the ways to address this issue is through the options given by the statement. The concepts related to the continuity equation and the Bernoulli equation.

Through these two equations it is possible to observe the behavior of the fluid, specifically the velocity at a constant height.

By definition the equation of continuity is,

A_1V_1=A_2V_2

In the problem A_2 is 2A_1, then

A_1V_1=2A_1V_2

V_2 = \frac{V_1}{2}

<em>Here we can conclude that by means of the continuity when increasing the Area, a decrease will be obtained - in the diminished times in the area - in the speed.</em>

For the particular case of Bernoulli we have to

P_1 + \frac{1}{2}\rho V_1^2 = P_2 +\frac{1}{2}\rho V_2^2

P_2-P_1 = \frac{1}{2} \rho (V_1^2-V_2^2)

For the previous definition we can now replace,

P_2-P_1 = \frac{1}{2} \rho (V_1^2-(\frac{V_1}{2})^2)

\Delta P =  \frac{3}{8} \rho V_1^2

<em>Expressed from Bernoulli's equation we can identify that the greater the change that exists in pressure, fluid velocity will tend to decrease</em>

The correct answer is B: "If we increase A2 then by the continuity equation the speed of the fluid should decrease. Bernoulli's equation then shows that if the velocity of the fluid decreases (at constant height conditions) then the pressure of the fluid should increase"

4 0
2 years ago
Other questions:
  • The pesticide DDT was first made by a chemical company in 1939 and became widely used worldwide. Evidence that DDT builds up in
    5·2 answers
  • A 59.7 g piece of metal that had been submerged in boiling water was quickly transferred into 60.0 mL of water initially at 22.0
    14·1 answer
  • Two spherical drops of mercury each have a charge of 0.10 nC and a potential of 300 V at the surface. The two drops merge to for
    7·1 answer
  • Male Rana catesbeiana bullfrogs are known for their loud mating call. The call is emitted not by the frog's mouth but by its ear
    14·1 answer
  • An end of a light wire rod is bent into a hoop of radius r. The straight part of the rod has length l; a ball of mass M is attac
    10·1 answer
  • a rectangular coil of 25 loops is suspended in a field of 0.20wb/m2.the plane of coil is parallel to the direction of the field
    7·1 answer
  • The oscilloscope can be thought of as a plotting machine. What is plotted on the a axis? What is plotted on the y axis? If you t
    5·1 answer
  • According to the Revere and Black (2003) article, processes that result in an error probability of 0.000070 should be recognized
    8·1 answer
  • A young child hold a string attached to a balloon. What is the reaction force to the balloon pulling up on the earth?
    12·1 answer
  • You are at a stop light in your car, stuck behind a red light. Just before the light is supposed to change, a fire engine comes
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!