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3 years ago

Which sequence correctly reflects the order in which electrical charges occur during an action potential, from first to last?

1 answer:

4 0

This sequence refer to how neurons send messages electrochemically. When the neurons are at rest, they are at its resting potential at -70 millivolts. If the neurons in the brain send messages, a spike would occur until it reaches the threshold potential at -55 mV. If it reaches the threshold potential, then an action potential occurs.Hence, the sequence would be letter C.

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You have 1.2kg of (AU)gold (that's quite a bit of money at $1839/ounce). Using a heat source you apply 3096 J to the gold and re

melamori03 [73]

Answer:

129 J/Kg°C

Explanation:

Given :

Mass of gold, m = 1.2kg

Quantity of heat applied, Q = 3096 J

Temperature, t2 = 40°C

Temperature, t1 = 20°C

Change in temperature, dt = (40-20)°C = 20°C

Using the relation :

Q = mcdt

Where, C = specific heat capacity of gold

3096 = 1.2kg * C * 20°C

3096 J = 24kg°C * C

C = 3096 J / 24 kg°C

C = 129 J/Kg°C

7 0

2 years ago

A 60 kg person sits in a chair. How much does the earth pull on the person? (Acceleration due to gravity is -10m/s2) F = mxa → F

MA_775_DIABLO [31]

Answer:

600N(downwards)

Explanations

600N(downwards)

Mas of the person = 60kg

Acceleration due to gravity = -10m/s²

To get the earths pull on the person, we will use the Newton second law of motion;

Force = mass * acceleration;

Force = 60 * -10

Force- -600N

Hence the earth gravitational pull on the person is 600N(downwards). It is downwards due to the negative sign.

7 0

2 years ago

A freight car moves along a friction less level railroad track at constant speed. The car is open on top. A large load of coal i

maxonik [38]

Answer:

The velocity of the freight car decreases.

Explanation:

This question is answered by the conservation of momentum principle.

When the freight car is moving at a certain speed, it has a constant momentum.

We will call this M1.

The equation for M1 will be:

M1 = Mass * Speed

Now when the coal is dumped into the freight car, the Mass increases.

Since conservation of momentum states that the momentum will remain the same. We have:

M1 = (Mass of freight + Mass of coal) * Speed

Since M1 is constant, if the mass increases, the speed had to decrease to keep the equation true.

8 0

3 years ago

La tension que se transmite en la cuerda BD es de 75 lb. Calcula el momento de fuerza generada por la cuerda respecto al punto C

Bas_tet [7]

Answer:

Mc = 1920[lb*in]

Explanation:

Para poder solucionar este problema debemos realizar un análisis estático, por tal motivo lo primero es realizar un diagrama de cuerpo libre con las respectivas fuerzas actuando sobre la barra ABC. DE igual manera calcular la geometría de la configuración mostrada.

El diagrama de cuerpo libre se puede ver en la imagen adjunta, con la solución de este problema.

Lo primero es determinar el angulo t, el cual por medio de las propiedades del triangulo rectángulo se puede determinar.

Con este angulo (t) ya determinado, fijamos la atención en el triangulo BCD, este triangulo no es rectángulo, pero por medio de la ley de senos podemos determinar el angulo omega.

Después de determinar el angulo omega, restamos el angulo (t) para poder determinar el angulo (a).

Seguidamente realizamos una sumatoria de momentos alrededor del punto C, utilizado las respectivas fuerzas con los ángulos descompuestos.

El momento en el punto C es de 1920 [Lb*in].

Nota: ya que no se menciona la fuerza en el punto A, esta se desprecia y no se tiene en cuenta en los calculos. En la imagen adjunta se puede ver el procedimiento desarrollado.

7 0

2 years ago

What will be the value of both charges if they are 5 cm apart and suffer a

Mrac [35]

Answer:

$\boxed{q = 1.2 \times {10}^{ - 6} C}$

Explanation:

$f_e = \frac{{q}^{2}k }{ {r}^{2} } \\ q = \sqrt{ \frac{f_e( {r}^{2} )}{k} } = \sqrt{ \frac{5.2(5 \times {10}^{ - 2} )^{2} }{9 \times {10}^{9} } } \\ q =\sqrt{ \frac{5.2(5 \times {10}^{ - 2} )^{2} }{9 \times {10}^{9} } } = \sqrt{ \frac{0.013}{9 \times {10}^{9} } } \\ q = 1.2 \times {10}^{ - 6}$

3 0

2 years ago