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3 years ago

How is thermal energy naturally transferred between objects?

1 answer:

5 0

The second law of thermodynamics establishes restrictions on the flow of thermal energy between two bodies. This law states that the energy does not flow spontaneously from a low temperature object T1, to another object that is at a high temperature T2.

For example. Suppose you place your cell phone on the table. Your phone is at a temperature of 40 ° C and the table is at 19 ° C. Then, it is impossible for the table to spontaneously transfer its thermal energy to the telephone, and so that the table gets colder and the telephone warmer.

Finally we can say that the correct option is B: From the hotter object to the cooler object

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The rms (root-mean-square) speed of a diatomic hydrogen molecule at 50∘C is 2000 m/s. Note that 1.0 mol of diatomic hydrogen at

denis-greek [22]

Answer:

A) d. (1/4)(2000m/s) = 500 m/s

B) c. 4000 J

C) f. None of the above (2149.24 m/s)

Explanation:

The translational kinetic energy of a gas molecule is given as:

K.E = (3/2)KT

where,

K = Boltzman's Constant = 1.38 x 1^-23 J/K

T = Absolute Temperature

but,

K.E = (1/2) mv²

where,

v = root mean square velocity

m = mass of one mole of a gas

Comparing both equations:

(3/2)KT = (1/2) mv²

v = √(3KT)/m _____ eqn (1)

FOR HYDROGEN:

v = √(3KT)/m = 2000 m/s _____ eqn (2)

FOR OXYGEN:

velocity of oxygen = √(3KT)/(mass of oxygen)

Here,

mass of 1 mole of oxygen = 16 m

velocity of oxygen = √(3KT)/(16 m)

velocity of oxygen = (1/4) √(3KT)/m

using eqn (2)

velocity of oxygen = (1/4)(2000 m/s) = 500 m/s

K.E = (3/2)KT

Since, the temperature is constant for both gases and K is also a constant. Therefore, the K.E of both the gases will remain same.

K.E of Oxygen = K.E of Hydrogen

K.E of Oxygen = 4000 J

using eqn (2)

At, T = 50°C = 323 k

v = √(3KT)/m = 2000 m/s

m = 3(1.38^-23 J/k)(323 k)/(2000 m/s)²

m = 3.343 x 10^-27 kg

So, now for this value of m and T = 100°C = 373 k

v = √(3)(1.38^-23 J/k)(373 k)/(3.343 x 10^-27 kg)

v = 2149.24 m/s

8 0

4 years ago

A ball is dropped from rest. how fast is the ball going after 3 seconds

Airida [17]

Answer:

v = 29.4m/s

Explanation:

Since the ball is dropped at rest,

u = 0m/s

a = 9.81m/s²

Using

v = u + at

After 3 seconds,

v = 0 + (9.81)(3)

v = 29.4m/s

5 0

3 years ago

Three identical resistors have an equivalent resistance 15.6 ohm when they are connected in series. What is the resistance for e

attashe74 [19]

Answer:

$R=5.2\ \Omega$

Explanation:

In series combination, the equivalent resistance is given by :

$R_{eq}=R_1+R_2+R_3+...$

Let the identical resistors be R. We have, $R_{eq}=15.6\ \Omega$

So,

$R+R+R=15.6\\\\3R=15.6\\\\R=\dfrac{15.6}{3}\\\\R=5.2\ \Omega$

So, the resistance of each resistor is $5.2\ \Omega$ .

4 0

3 years ago

Evaporation only occurs at the surface of a liquid

Veseljchak [2.6K]

yes

evaporation starts on the surface

8 0

4 years ago

What is theory of electromagnetism?

Soloha48 [4]

Explanation:

Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force is carried by electromagnetic fields composed of electric fields and magnetic fields, and it is responsible for electromagnetic radiation such as light.

5 0

3 years ago

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