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3 years ago

A 15 cm3 block of gold weighs 2.8 N. It is carefully submerged in a tank of mercury. One cm3 of mercury weighs 0.13 N.

1 answer:

5 0

The density of gold is 2.8 N / 15 = 0.18 units
The density of mercury is 0.13/1 = 0.13 units

Since the density of gold is more than density of mercury, it will sink.
Since the gold will sink, it will displace mercury, but less than its own volume

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2 years ago

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Sort the processes based on the type of energy transfer they involve.

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Hi, thank you for posting your question herein Brainly.

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2 years ago

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An electron and a proton each have a thermal kinetic energy of 3kBT/2. Calculate the de Broglie wavelength of each particle at a

S_A_V [24]

Answer:

Given:

Thermal Kinetic Energy of an electron, $KE_{t} = \frac{3}{2}k_{b}T$

$k_{b} = 1.38\times 10^{- 23} J/k$ = Boltzmann's constant

Temperature, T = 1800 K

Solution:

Now, to calculate the de-Broglie wavelength of the electron, $\lambda_{e}$ :

$\lambda_{e} = \frac{h}{p_{e}}$

$\lambda_{e} = \frac{h}{m_{e}{v_{e}}$ (1)

where

h = Planck's constant = $6.626\times 10^{- 34}m^{2}kg/s$

$p_{e}$ = momentum of an electron

$v_{e}$ = velocity of an electron

$m_{e} = 9.1\times 10_{- 31} kg$ = mass of electon

Now,

Kinetic energy of an electron = thermal kinetic energy

$\frac{1}{2}m_{e}v_{e}^{2} = \frac{3}{2}k_{b}T$

$}v_{e} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{e}}}$

$}v_{e} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{9.1\times 10_{- 31}}}$

$v_{e} = 2.86\times 10^{5} m/s$ (2)

Using eqn (2) in (1):

$\lambda_{e} = \frac{6.626\times 10^{- 34}}{9.1\times 10_{- 31}\times 2.86\times 10^{5}} = 2.55 nm$

Now, to calculate the de-Broglie wavelength of proton, $\lambda_{e}$ :

$\lambda_{p} = \frac{h}{p_{p}}$

$\lambda_{p} = \frac{h}{m_{p}{v_{p}}$ (3)

where

$m_{p} = 1.6726\times 10_{- 27} kg$ = mass of proton

$v_{p}$ = velocity of an proton

Now,

Kinetic energy of a proton = thermal kinetic energy

$\frac{1}{2}m_{p}v_{p}^{2} = \frac{3}{2}k_{b}T$

$}v_{p} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{p}}}$

$}v_{p} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{1.6726\times 10_{- 27}}}$

$v_{p} = 6.674\times 10^{3} m/s$ (4)

Using eqn (4) in (3):

$\lambda_{p} = \frac{6.626\times 10^{- 34}}{1.6726\times 10_{- 27}\times 6.674\times 10^{3}} = 5.94\times 10^{- 11} m = 0.0594 nm$

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3 years ago

In which condition is relative velocity known by adding the velocity od the first body and that of the second body ?

Softa [21]

Answer:

when a two bodies A and B are moving at an angle 180° with each other then the relative velocity is the sum of bodies the velocity .i.e,

when the bodies move the opposite direction

then their relative velocity is the sum of individual velocities.

3 0

2 years ago

A force of 200 N stretches a spring 30 cm. What is the spring constant of the spring? How far would this spring stretch with a f

bija089 [108]

Hooke's Law

F = k. Δx

Δx = 30 cm = 0.3 m

200 = k . 0.3

$\tt k =\dfrac{200}{0.3}= 666.6$

the spring stretch for 100 N:

$\tt \Delta x=\dfrac{100}{666.6}=0.15=15\:cm$

4 0

2 years ago