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
arlik [135]
3 years ago
10

Why do people tend to cup their hands around listeners' ears when whispering to them?

Physics
2 answers:
dezoksy [38]3 years ago
8 0
So others don't hear what they are saying
Alekssandra [29.7K]3 years ago
4 0
So that sound is reflected inside the space between one's mouth and hands itself
You might be interested in
Two objects, one having twice the mass of the other, are initially at rest. Two forces, one twice as big as the other, act on th
Elodia [21]

<em><u>Note: There is no image to take as a reference, so I'm assuming F2 directed to the right and F1 to the left, and F2=2F1</u></em>

Answer:

\displaystyle a=\frac{F}{3M}

<em>to the right</em>

Explanation:

<u>Net Force</u>

When several forces are applied to a particle or a system of particles, the net force is the sum of them all, considering each force as a vector. As for the second Newton's law, the total force equals the product of the mass by the acceleration of the system:

\vec F_n=m\cdot \vec a

If the net force is zero, then the system of particles keeps at rest or at a constant velocity.

The system of particles described in the question consists of two objects of masses m1=M and m2, where

m_2=2m_1=2M

Two forces F1=F and F2 act individually on each object in opposite directions and

F_2=2F_1=2F

We don't get to see any image to know where the forces are applied to, so we'll assume F2 to the right and F1 to the left.

The net force of the system of particles is

F_n=2F-F=F

The mass of the system is

m_t=m_1+m_2=3M

Thus, the acceleration of the center of mass of the system is

\displaystyle a=\frac{F}{3M}

Since F2 is greater than F1, the direction of the acceleration is to the right.

Note: If the forces were opposite than assumed, the acceleration would be to the left

6 0
3 years ago
A(n) __________ is a fast-flowing river of air at the boundary between the troposphere and stratosphere.
Ivahew [28]
<span>This is the jet stream. This air current flows from west to east along a typically-meandering path that is often used as a predictor of weather conditions. These currents are typically formed from the fact that the equator is warmer than the poles, and this allows the different-density air masses to develop an eastward-moving component.</span>
7 0
4 years ago
In this problem you will consider the balance of thermal energy radiated and absorbed by a person.Assume that the person is wear
Viefleur [7K]

Answer:P=14.6 W

Explanation:

According to the Stefan-Boltzmann law for real radiating bodies:

P=\sigma A \epsilon T^{4} (1)

Where:

P is the energy radiated (in Watts)

\sigma=5.67(10)^{-8}\frac{W}{m^{2} K^{4}} is the Stefan-Boltzmann's constant.  

A is the Surface area of the body  

T=30\°C + 273.15= 303.15 K is the effective temperature of the body (its surface absolute temperature) in Kelvin

\epsilon=0.6 is the body's emissivity

On the other hand, we are told the human body is roughly approximated to a cylinder of length L=2.0m and circumference C=0.8m.

The circumference of a circle is:C=0.8m=2 \pi r where r is the radius. Hence r=\frac{0.8m}{2 \pi}=0.1273 m.

Now we have to input this value for r  in the Area of a cylinder formula:

A=\pi r^{2}L

A=\pi (0.1273 m)^{2}(2 m)

A=0.0509 m^{2} (2)

Substituting (2) in (1):

P=(5.67(10)^{-8}\frac{W}{m^{2} K^{4}}) (0.0509 m^{2}) (0.6) (303.15 K)^{4} (3)

Finally:

P=14.62 W \approx 14.6 W

5 0
3 years ago
Factfile about eclips
MAXImum [283]
Its quite hard to give you facts over this but just type into google facts about the sonar/lunar eclipse.

6 0
4 years ago
During the main sequence lifetime of a star of any mass, the core of the star will be composed mainly of _____.​
EleoNora [17]
Gas my friend enjoy!!!!
7 0
3 years ago
Other questions:
  • A car accelerates uniformly from rest to a speed of 58.3 mi/h in 9.47 s. Find the constant acceleration of the car.
    15·1 answer
  • 1. Explain the direction of gravity’s pull
    7·2 answers
  • A car accelerates from rest at 4 m/s^2. What is the velocity of the car after 4 seconds?
    14·1 answer
  • Which of the following phrases does not describe a motor?
    15·1 answer
  • (WILL MARK BRAINLIEST and 25pts) Another term for angular distance is
    14·2 answers
  • A 6 ft tall person walks away from a 10 ft lamppost at a constant rate of 5 ft/s. What is the rate (in ft/s) that the tip of the
    12·1 answer
  • Find initial velocity and time in air​
    5·1 answer
  • When you used the energy in our body to pull the rubber band, it was transformed into elastic potential energy. We know that ene
    7·1 answer
  • What is renewable source of energy ​
    8·2 answers
  • Radioactive nuclei decay to become unstable. Is this true or false?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!