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2 years ago

Which of the following statements are true?

Physics

1 answer:

aleksley [76]2 years ago

5 0

Good conductors of electricity have larger conductivity values than insulators.

A material that obeys Ohm's law reasonably well is called an ohmic conductor or a linear conductor.

The resistance of a conductor is proportional to the conductivity of the material of which the conductor is composed.

Answer: Options 1, 2 and 4.

<u>Explanation:</u>

In physics and electrical engineering, a conductor is an article or kind of material that permits the progression of charge in at least one headings. Materials made of metal are basic electrical conduits.

Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them. Most atoms hold on to their electrons tightly and are insulators.

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A projectile fired up into the air at an angle has a range of 235 m and a flight time of 47 s.

madam [21]

<h2>Answer:5 $ms^{-1}$ ,133.6 $m$ ,51.18 $ms^{-1}$ </h2>

Explanation:

Let $v_{x}$ , $v_{y}$ be the horizontal and vertical components of velocity.

Question a:

Horizontal component of velocity is the ratio of range and time of flight.

So,horizontal component of velocity is $\frac{235}{47}=5ms^{-1}$

So, $v_{x}=5ms^{-1}$

Question b:

Time of flight= $\frac{2v_{y}}{g}$

So, $v_{y}=\frac{47\times 9.8}{2}=51.18ms^{-1}$

Maximum height is given by $\frac{v_{y}^{2}}{2g}$

So,maximum height is $\frac{51.18^{2}}{2\times 9.8}=133.6m$

Question c:

The vertical velocity is already calculated in Question b.

$v_{y}=51.18ms^{-1}$

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2 years ago

The element radon is at the opposite end of the range, with the lowest specific heat of all naturally occurring elements. Radon'

allochka39001 [22]

Explanation:

Q = mc∆T

= (0.34 kg)(94 J/kg-°C)(25°C)

= 799 J

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3 years ago

Nerve cells transmit electric signals through their long tubular axons. These signals propagate due to a sudden rush of Na+ ions

iren [92.7K]

Answer:

$I = \frac{9.12x10^{-8} C}{0.007 s}= 1.30285 x10^{-5} \frac{C}{s}=1.30285 x10^{-5} A = 13.02 \mu A$

Explanation:

For this case we have the following info given:

Number of Na+ ions $5.7 x10^{11} ions$

Each ion have a charge of +e and the crage of the electron is $1.6 x10^{-19}C$

The time is given $t = 7 ms$ if we convert this into seconds we got:

$t = 7ms * \frac{1s}{1000 ms}= 0.007s$

Now we can use the following formula given from the current passing thourhg a meter of nerve axon given by:

$Q = Ne$

Where N represent the number of ions, e the charge of the electron and Q the total charge

If we replace on this case we have this:

$Q= 5.7x10^{11} * (1.6 x10^{-19}C) = 9.12x10^{-8} C$

And from the general definition of current we know that:

$I =\frac{Q}{t}$

And since we know the total charge Q and the time we can replace:

$I = \frac{9.12x10^{-8} C}{0.007 s}= 1.30285 x10^{-5} \frac{C}{s}=1.30285 x10^{-5} A = 13.02 \mu A$

The current during the inflow charge in the meter axon for this case is $13.02 \mu A$

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3 years ago

A stationary rock on a hill has

Mekhanik [1.2K]

Answer: potential energy but no kinetic energy

Explanation:

Since the rock is stationary, velocity is zero, therefore no kinetic energy,but there's potential energy because the rock is at rest,

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2 years ago

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Pani-rosa [81]

It typically take longer for a heavier object to slow down therefor, a train will take more time. <span />

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2 years ago

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