What is the kinetic energy of a jogger with a mass of 70.8 kg traveling at a speed of 2.4 m/s?

The units we use to measure the sound intensity level are _____.

Sergio039 [100]

Answer:

decibels (dB)

Explanation:

The sound intensity level is a quantity derived from the sound intensity.

The intensity of a wave is defined as the power of the source of the wave divided by the area through which the power of the wave is spread, mathematically:

$I=\frac{P}{A}$

where

P is the power of the source

$A=4\pi r^2$ is the surface area over which the wave spreads (assuming that the wave propagates in all directions, it corresponds to the surface area of a sphere of radius $r$ , where r is the distance between the source of the wave and the observer)

For sound waves, the intensity is often expressed using another unit, called decibel (dB), defined as follows:

$\beta(dB)=10Log_{10}(\frac{I}{I_0})$

where

$\beta$ is the sound intensity level in decibels

I is the intensity of the sound wave

$I_0=1\cdot 10^{-12} W/m^2$ is the threshold intensity of a sound that a person can normally hear.

3 0

2 years ago

Time period of a simple pendulum is measured at Karachi. What change will occur in the time period, if it is measured on mount e

Reil [10]

The period of a pendulum is given by $T=2 \pi \sqrt{ \frac{l}{g} }$
since Karachi is near sea level, g is larger than it is on Mt. Everest. That means the pendulum will have a larger period on Mt. Everest than it would in Karachi.

5 0

2 years ago

A positive test charge of 5.00 E-5 C is places in an electric field. The force on it is 0.751 N. The magnitude of the electric f

zalisa [80]

Explanation:

Charge=5.00 E-5

Force=0.751N

F=qE

0.751=5.00 E-5*E

E=1.502*10⁴

option a

8 0

3 years ago

Read 2 more answers

The membrane that surrounds a certain type of living cell has a surface area of 5.1 x 10-9 m2 and a thickness of 1.4 x 10-8 m.

ziro4ka [17]

a) The charge on the outer surface is $1.2\cdot 10^{-12} C$

b) The number of ions is $7.5\cdot 10^6$

Explanation:

a)

The membrane behaves as a parallel plate capacitor, whose capacity is given by the equation

$C=\frac{k\epsilon_0 A}{d}$

where

k = 4.3 is the dielectric constant

$\epsilon_0 =8.85\cdot 10^{-12} F/m$ is the vacuum permittivity

$A=5.1\cdot 10^{-9} m^2$ is the surface area

$d=1.4\cdot 10^{-8} m$ is the distance between the two plates

Substituting,

$C=\frac{(4.3)(8.85\cdot 10^{-12})(5.1\cdot 10^{-9})}{1.4\cdot 10^{-8}}=1.4\cdot 10^{-11} F$

The capacity of the membrane is related to the potential difference between the two surfaces by

$C=\frac{Q}{\Delta V}$

where here we have

Q = excess charge on one surface

$\Delta V = 85.5 mV = 0.0855 V$ is the potential difference between the two surfaces

Solving for Q, we find

$Q=C\Delta V=(1.4\cdot 10^{-11})(0.0855)=1.2\cdot 10^{-12} C$

b)

We said that the net charge on the outer surface is

$Q=1.2\cdot 10^{-12} C$

The charge of one K+ ions is equal to the electron charge

$+e=1.6\cdot 10^{-19} C$

Therefore, the number of ions on the outer surface can be found by dividing the total charge by the charge of a single ion:

$N=\frac{Q}{e}=\frac{1.2\cdot 10^{-12}}{1.6\cdot 10^{-19}}=7.5\cdot 10^6$

Learn more about capacity:

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brainly.com/question/8892837

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#LearnwithBrainly

6 0

2 years ago

Is the refraction different entering medium that has a higher index of refraction compared to entering amedium that has a lower

oee [108]

Answer:

Yes

Explanation:

The speed of light when it travels through glass, diamond, etc, the light travels at different speed from the speed of light. Speed of the light in material is related to the index of refraction.

The change in speed which occurs when the light passes from one medium to the another is responsible for bending of the light which is called as refraction.

<u>When the light goes into a medium with the higher index of the refraction, light bends towards normal. Conversely, if the light traveling goes from higher refractive index to lower refractive index, it will bend away from the normal. </u>

<u>Hence, the refraction is different in both the scenario.</u>

6 0

2 years ago