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3 years ago

The sequence of shifts in the electrical charge of a neuron is called

Physics

1 answer:

sweet-ann [11.9K]3 years ago

8 0

Answer:

The sequence of shifts in the electrical charge of a neuron is called Action Potential.

Explanation:

An action potential occurs when a neuron sends information down an axon, away from the cell body. Neuroscientists also use the terms, spike or impulse.

An Action Potential takes place in four steps:

Step 1:

Certain chemicals like neurotransmitters bind to dendrites and open special channels called stimulus gated channels.

Step 2:

Here comes depolarization in which neuron undergoes a shift in charge distribution.Charge reaches -59 mV. Positive sodium ions move into the cell and neuron becomes less negative(positive).

Step 3:

Repolarization occurs when the charge reaches a certain limit( 30 mV). Na+ channels stop and K+ channels open resulting in K+ ions moving out of the cell to make the neuron negatively charged again.

Step 4:

Hyperpolarization: K+ ions floods back at such a speed that a charge of -75 mV is reached for a very short period of time before resting potential is reached again.

Here, a neuron is at resting potential when it is not sending messages.

Action potential is the state in which a neuron sends messages down the axon away from the cell body. Action Potential fires when depolarization reaches -55 mV.

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Problem 21-40a:

Greeley [361]

Answer:

Part a)

$\frac{F_e}{F_g} = 2.74 \times 10^{12}$

Part b)

$q = 3.37 \times 10^{-4} C$

Explanation:

As we know that electric force on electric charge is given as

$F = qE$

here we have

$q = 1.6 \times 10^{-19}C$

E = 153 N/C

now force is given as

$F = (1.6 \times 10^{-19})(153) = 2.45 \times 10^{-17} N$

Gravitational force on electric charge near surface of earth is given as

$F_g = mg$

$F_g = (9.1 \times 10^{-31})(9.81) = 8.93 \times 10^[-30} N$

now the ratio of two forces is given as

$\frac{F_e}{F_g} = \frac{2.45 \times 10^{-17}}{8.93 \times 10^{-30}}$

$\frac{F_e}{F_g} = 2.74 \times 10^{12}$

Part b)

Now the ball is balanced by the electric force and the force of gravity on it

so here we have

$F_g = qE$

$mg = qE$

$(5.25 \times 10^{-3})(9.81) = q(153)$

here we have

$q = 3.37 \times 10^{-4} C$

8 0

4 years ago

How strong an electric field is needed to accelerate electrons in an X-ray tube from rest to one-tenth the speed of light in a d

Bond [772]

Answer:

E= 50.1*10³ N/C

Explanation:

Assuming no other forces acting on the electron, if the acceleration is constant, we can use the following kinematic equation in order to find the magnitude of the acceleration:

$vf^{2} -vo^{2} = 2*a*x$

We know that v₀ = 0 (it starts from rest), that vf = 0.1*c, and that x = 0.051 m, so we can solve for a, as follows:

$a = \frac{vf^{2}}{2*x} = \frac{(3e7 m/s)^{2} }{2*0.051m} =8.8e15 m/s2$

According to Newton's 2nd Law, this acceleration must be produced by a net force, acting on the electron.

Assuming no other forces present, this force must be due to the electric field, and by definition of electric field, is as follows:

F = q*E (1)

In this case, q=e= 1.6*10⁻19 C

But this force, can be expressed in this way, according Newton's 2nd Law:

F = m*a (2) ,

where m= me = 9.1*10⁻³¹ kg, and a = 8.8*10¹⁵ m/s², as we have just found out.

From (1) and (2), we can solve for E, as follows:

$E=\frac{me*a}{e} =\frac{(9.1e-31 kg)*(8.8e15m/s2)}{1.6e-19C} = 50.1e3 N/C$

⇒ E = 50.1*10³ N/C

3 0

4 years ago

Two technicians are discussing testing MAP sensors. Technician A says that the MAP sensor should be replaced if anything comes o

irinina [24]

The statements from both Technicians A and B are correct.

Answer: Option C

<u>Explanation:</u>

A typical MAP sensors comprises with a ceramic or silicon wafers, sealed with an ideal vacuum on one side and a suction manifold on the other. When the engine (motor) vacuum varies, the differential pressure across the board changes the output voltage or frequency to the MAP sensor. So, sensor vacuum to be increased if injection pulse widths increase.

Most pressure sensors operate at 5 volts from a computer and return a signal (voltage or frequency) based on the pressure applied to the sensor (vacuum). When testing the MAP sensor, make sure that the vacuum hose and hose connections are tightly connected to the engine vacuum source. According to this, concluding that the statements from both technicians are correct.

6 0

4 years ago

PLEASE HELP!!!

ololo11 [35]

Answer:

asd

Explanation:

4 0

3 years ago

What is the constant acceleration of gravity on earth

Ira Lisetskai [31]

Answer:

9.807 m/s²

Explanation:

3 0

3 years ago