All categories

2 years ago

Sound that reaches the ears after bouncing off a wall or a floor is called _____.

Physics

2 answers:

andrew11 [14]2 years ago

8 0

Answer:

Indirect sound

BartSMP [9]2 years ago

3 0

Answer:

ecolocation I think but it is not for human ears

You might be interested in

The pressure in an automobile tire depends on the temperature of the air in the tire. When the air temperature is 25°C, the pres

12345 [234]

Answer:0.0704 kg

Explanation:

Given

initial Absolute pressure $(P_1)$ =210+101.325=311.325

$T_1=25^{\circ}\approx 298 K$

$V=0.025 m^3$

$T_2=50^{\circ}\approx 323 K$

as the volume remains constant therefore

$\frac{P_1}{T_1}=\frac{P_2}{T_2}$

$\frac{311.325}{298}=\frac{P_2}{323}$

$P_2=337.44 KPa$

therefore Gauge pressure is 337.44-101.325=236.117 KPa

Initial mass $m_1=\frac{P_1V}{RT_1}=\frac{311.325\times 0.025}{0.0287\times 298}$

$m_1=0.91 kg$

Final mass $m_2=\frac{P_2V}{RT_2}=\frac{311.325\times 0.025}{0.0287\times 323}$

$m_2=0.839$

Therefore $m_1-m_2$ =0.91-0.839=0.0704 kg of air needs to be removed to get initial pressure back

4 0

3 years ago

A body which has surface area 5cm² and temperature of 727°C radiates 300J of energy in one minute. Calculate it's emissivity giv

cestrela7 [59]

<h2>Answer: 0.17</h2>

Explanation:

The Stefan-Boltzmann law establishes that a black body (an ideal body that absorbs or emits all the radiation that incides on it) "emits thermal radiation with a total hemispheric emissive power proportional to the fourth power of its temperature":

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

Where:

$P=300J/min=5J/s=5W$ is the energy radiated by a blackbody radiator per second, per unit area (in Watts). Knowing $1W=\frac{1Joule}{second}=1\frac{J}{s}$

$\sigma=5.6703(10)^{-8}\frac{W}{m^{2} K^{4}}$ is the Stefan-Boltzmann's constant.

$A=5cm^{2}=0.0005m^{2}$ is the Surface area of the body

$T=727\°C=1000.15K$ is the effective temperature of the body (its surface absolute temperature) in Kelvin.

However, there is no ideal black body (ideal radiator) although the radiation of stars like our Sun is quite close. So, in the case of this body, we will use the Stefan-Boltzmann law for real radiator bodies:

$P=\sigma A \epsilon T^{4}$ (2)

Where $\epsilon$ is the body's emissivity

(the value we want to find)

Isolating $\epsilon$ from (2):

$\epsilon=\frac{P}{\sigma A T^{4}}$ (3)

Solving:

$\epsilon=\frac{5W}{(5.6703(10)^{-8}\frac{W}{m^{2} K^{4}})(0.0005m^{2})(1000.15K)^{4}}$ (4)

Finally:

$\epsilon=0.17$ (5) This is the body's emissivity

3 0

3 years ago

a machine gun fires 10 rounds per second the speed of the bullets is 300 m/s. what is the distance in the air between the flying

vovangra [49]

<span>(300 m/s)/(10 r/s) = 30 m/round.</span>

4 0

3 years ago

A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a

skelet666 [1.2K]

Answer:

B.) a wheel and axle and a lever

Explanation:

P.S - The exact question is -

Given - A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.

To find - Which simple machines make up a wheelbarrow?

A.) a pulley and an inclined plane

B.) a wheel and axle and a lever

C.) a pulley and a wheel and axle

D.) a lever and a wedge

Proof -

The correct option is - B.) a wheel and axle and a lever

Wheelbarrows are used to carry more goods from place to place by using minimal force as compared when goods are carried by hand.

With this machine, During hauling people can save time.

4 0

3 years ago

Read 2 more answers

A brick is lying on a table in a state of static equilibrium. If the mass of the brick is 7.52 kilograms, what is the normal for

WARRIOR [948]

Answer:

-mg = -7.52*9.8 = - 73.696N

7 0

3 years ago