What is the kinetic energy of a 2000 kg car traveling at a speed of 30 m/s (?65 mph)?

Nonamiya [84]

A force is a push or pull to an object

4 0

4 years ago

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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#LearnwithBrainly

6 0

3 years ago

In the following diagrams the larger vector has a magnitude of 10, and the smaller

Anton [14]

the sum of vectors with the Pythagorean theorem allows us to find that the maximum magnitude occurs for the case:

d) the two vectors are parallel

Vectors are physical quantities that have modulus and direction, for example: force, velocity, acceleration, etc.

Vector algebra has defined the sum, the product by a scalar and by a vector. The modulus and the direction of the resulting vector must be encoded.

The sum of two quantities is done using the Pythagorean theorem

c² = a² + b²

where c is the resultant called hypotenuse, a and b are the summing vectors called legs; trigonometry is used for the direction.

Let's apply this expression to the present case

a, b) perpendicular vectors

c² = a² + b²

c = $\sqrt{6^2+10^2}$

c = 11.7

the magnitude is the same in both cases, changing the direction of the vector

c) Antiparallel vectors

For this case the vectors are collinear, so the sum reduces to the algebraic addition

c = a-b

c = 6 -10

c = -4

d) parallel vectors

c = a + b

c = 4 + 10

c = 14

We can see that the vectors addition gives their maximum and minimum values when the vectors are collinear.

In conclusion using the vectors addition we find that the correct answer is

d) the two vectors are parallel

learn more about vector addition here:

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6 0

3 years ago

Which of the following codes is used to report the removal of 37 skin tags by electrosurgical destruction?

Tema [17]

Are there any answer choices??

7 0

3 years ago

A wave has a wavelength of 5 meters and a frequency of 3 hertz. What is the speed of the wave?

otez555 [7]

A sound wave in a steel rail has a frequency of 620 Hz and a wavelength of 10.5 ... Find the speed of a wave with a wavelength of 5 m and a frequency of 68 Hz.

8 0

3 years ago