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3 years ago

What is a substances specific heat

Physics

2 answers:

Romashka [77]3 years ago

7 0

Answer:

The amount of heat a substance can hold.

Explanation:

MrRa [10]3 years ago

4 0

It's the amount of heat you need to pump into 1 gram of the substance
in order to raise its temperature 1°C.

Different substances can have some wildly different values of specific heat.
The specific heat of water, potatoes, and rocks are especially high. That means
that those substances 'hold' a lot of heat ... which is why, before electric heating
pads were invented, rubber bags with these substances were used to warm up a
cold bed or to reduce the pain in a sore muscle.

Specific Joules:
heat of:     per gm-°C

Lead      0.13
Copper    0.38
Iron      0.45
Aluminum   0.9
Water       4.2
Helium 5.2
Hydrogen 14.3

Don't quite understand the idea yet ?
Here's one way I like to think of it:

Here I have a soda straw, with the bottom end closed and some water in it.
How much water would you have to add to the straw to fill it 1 inch higher ?
Not much, right ?

OK. Now, here I have a beer barrel that's maybe about half full of water.
How much water would you have to add to the barrel to fill it 1 inch higher ?
MORE than the soda straw, right ?

OK. Now, here I have an olympic swimming pool with some water in it.
How much water would you have to add to the pool to fill it 1 inch higher ?
A lot ? I agree.
How much ? I don't know.
But definitely MORE than the straw or the barrel.

This is the way I understand specific heat:

-- The AMOUNT of water is like the heat-energy in the substance.
-- The DEPTH of the water is like the temperature of the substance.
-- The more water you pour into it, the deeper it gets.
-- The more heat you pour into it, the warmer it gets.
-- But some substances are "wider" than others.
. . . . . Lead is very skinny, like the straw.
      0.13 joule of heat added to a gram of it is enough to raise it 1°C.
. . . . . Water is a 'fatter' substance, like the barrel.
You have to pour 4.2 joules into a gram of it, to raise it 1°C.
. . . . . Hydrogen is incredibly fat, like the pool.
You have to pour 14.3 joules into 1 gram of it, to raise it 1°C.

==> Hydrogen needs 110 times as much heat energy added as
Lead needs, to make 1 gram of each substance 1°C warmer than
they are now.
The specific heat of Hydrogen is 110 times the specific heat of Lead !

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Explanation:

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2 years ago

A 1.60 m cylindrical rod of diameter 0.550 cm is connected to a power supply that maintains a constant potential difference of 1

bija089 [108]

Answer:

Part a)

$\rho = 1.35 \times 10^{-5}$

Part b)

$\alpha = 1.12 \times 10^{-3}$

Explanation:

Part a)

Length of the rod is 1.60 m

diameter = 0.550 cm

now if the current in the ammeter is given as

$i = 18.7 A$

V = 17.0 volts

now we will have

$V = I R$

$17.0 = 18.7 R$

R = 0.91 ohm

now we know that

$R = \rho \frac{L}{A}$

$0.91 = \rho \frac{1.60}{\pi(0.275\times 10^{-2})^2}$

$\rho = 1.35 \times 10^{-5}$

Part b)

Now at higher temperature we have

$V = I R$

$17.0 = 17.3 R$

R = 0.98 ohm

now we know that

$R = \rho \frac{L}{A}$

$0.98 = \rho' \frac{1.60}{\pi(0.275\times 10^{-2})^2}$

$\rho' = 1.46 \times 10^{-5}$

so we will have

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Answer:

Part a)

$i = 1.55 A$

Part b)

$v_d = 1.4 \times 10^{-4} m/s$

Explanation:

Part a)

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$j = \frac{i}{A}$

now we have

$i = jA$

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$i = 1.55 A$

Part b)

now we have

$j = nev_d$

so we have

$n = 8.5 \times 10^{28}$

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

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$1.90 \times 10^6 = (8.5 \times 10^{28})(1.6 \times 10^{-19})v_d$

$v_d = 1.4 \times 10^{-4} m/s$

8 0

3 years ago

To aid in the prevention of tooth decay, it is recommended that drinking water contain 0.800 ppm fluoride, F−. How many grams of

Leviafan [203]

Answer:

2.23 × 10^6 g of F- must be added to the cylindrical reservoir in order to obtain a drinking water with a concentration of 0.8ppm of F-

Explanation:

Here are the steps of how to arrive at the answer:

The volume of a cylinder = ((pi)D²/4) × H

Where D = diameter of the cylindrical reservoir = 2.02 × 10^2m

H = Height of the reservoir = 87.32m

Therefore volume of cylindrical reservoir = (3.142×202²/4)m² × 87.32m = 2798740.647m³

1ppm = 1g/m³

0.8ppm = 0.8 × 1g/m³

= 0.8g/m³

Therefore to obtain drinking water of concentration 0.8g/m³ in a reservoir of volume 2798740.647m³, F- of mass = 0.8g/m³ × 2798740.647m³ = 2.23 × 10^6 g must be added to the tank.

Thank you for reading.

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3 years ago

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lukranit [14]

Answer:

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Greenhouse effect leads to increase in the temperature of the earth, melting of polar ice caps and possibly flooding due to a rise in sea levels.

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Answer:

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2 years ago