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
Sonbull [250]
4 years ago
9

Which force requires contact?

Physics
1 answer:
GuDViN [60]4 years ago
3 0

Answer:

I think its D too

Explanation:

You might be interested in
(a) If two sound waves, one in a gas medium and one in a liquid medium, are equal in intensity, what is the ratio of the pressur
GarryVolchara [31]

Answer:

(a) The ratio of the pressure amplitude of the waves is 43.21

(b) The ratio of the intensities of the waves is 0.000535

Explanation:

Given;

density of gas, \rho _g = 2.27 kg/m³

density of liquid, \rho _l = 972 kg/m³

speed of sound in gas, C_g = 376 m/s

speed of sound in liquid, C_l = 1640 m/s

The of the sound wave is given by;

I = \frac{P_o^2}{2 \rho C} \\\\P_o^2 = 2 \rho C I\\\\p_o = \sqrt{2 \rho CI}

Where;

P_o is the pressure amplitude

P_o_g= \sqrt{2 \rho _g C_gI} -------(1)\\\\P_o_l= \sqrt{2 \rho _l C_lI}---------(2)\\\\\frac{P_o_l}{P_o_g} = \frac{\sqrt{2 \rho _l C_lI}}{\sqrt{2 \rho _g C_gI}} \\\\\frac{P_o_l}{P_o_g} = \sqrt{\frac{2 \rho _l C_lI}{2 \rho _g C_gI} }\\\\ \frac{P_o_l}{P_o_g} = \sqrt{\frac{ \rho _l C_l}{ \rho _g C_g} }\\\\ \frac{P_o_l}{P_o_g} = \sqrt{\frac{ (972)( 1640)}{ (2.27)( 376)} }\\\\\frac{P_o_l}{P_o_g} = 43.21

(b) when the pressure amplitudes are equal, the ratio of the intensities is given as;

I = \frac{P_o^2}{2 \rho C}\\\\I_g = \frac{P_o^2}{2 \rho _g C_g}-------(1)\\\\I_l = \frac{P_o^2}{2 \rho _l C_l}-------(2)\\\\\frac{I_l}{I_g} = (\frac{P_o^2}{2 \rho _l C_l})*(\frac{2\rho_gC_g}{P_o^2} )\\\\\frac{I_l}{I_g} = \frac{\rho _gC_g}{\rho_lC_l} \\\\\frac{I_l}{I_g} = \frac{(2.27)(376)}{(972)(1640)}\\\\ \frac{I_l}{I_g} = 0.000535

3 0
3 years ago
what percentage of North American adults may be functioning below their potential due to prolonged exposure to stress
Yuliya22 [10]
I believe the percentage is between 15-20%. Stress is a well known factor that affects the performance of people.
6 0
3 years ago
A parsec is a measurement of: magnitude distance position speed
guajiro [1.7K]
A parsec is a measurement of distance.
6 0
3 years ago
Read 2 more answers
Harry Potter is chasing his nemesis Draco Malfoy during a quidditch match. Initially, Harry is 35m behind Draco, who has just sp
Sophie [7]

Answer:

the acceleration of harry is equal to 66.126 m/s²

Explanation:

given,

harry is 35 m behind Draco

speed of Draco = 40 m/s

original speed of harry = 50 m/s

acceleration = ?

time taken by the Draco

    t =\dfrac{r}{u} =\dfrac{75}{40}

     t = 1.875 s

distance covered by Harry

  d = 35 + 175 = 210 m

to calculate the acceleration of harry

s = u t+ \dfrac{1}{2}at^2

210 = 50\times 1.875+ \dfrac{1}{2}\times a\times 1.875^2

a × 3.516 × 0.5 = 116.25

a = 66.126 m/s²

hence, the acceleration of harry is equal to 66.126 m/s²

3 0
4 years ago
Calculate the acceleration of an airplane that starts at rest and reaches a speed 45m/s in 9 seconds
sasho [114]

I believe the acceleration would be 5m/s

All you would need to do is divide the final speed by the time it took to get there. I am only about 80 sure this answer is correct, so take my advise only if you feel comfortable.

3 0
4 years ago
Read 2 more answers
Other questions:
  • Newton’s third law explains what happens when two objects ______.
    15·1 answer
  • what is the result of 6.2×10 to the fourth power times 3.3×10 to the second power express in scientific notation
    14·1 answer
  • Which one of the following terms is used to describe the bending of waves and subsequent spreading around obstacles or the edges
    8·1 answer
  • Question 1
    11·2 answers
  • B. A car moving at an initial speed vi applies its brakes and skids for some distance until coming to a complete stop. If the co
    9·1 answer
  • Help fast!!! I thought I understood but I don’t
    9·1 answer
  • One side of a seesaw carries a 21kg mass four meters from the fulcrum and a 25.5kg mass two meters from the fulcrum. To balance
    14·1 answer
  • A tennis player hit a .057-kg ball with a force of 40 N. The duration of the force was .05 s.
    12·1 answer
  • In ptolemy’s earth-centered model for the solar system, venus always stays close to the sun in the sky and, because it always st
    14·1 answer
  • To determine whether a celestial body is approaching or receding from earth, astronomers employ?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!