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3 years ago

The chimney of an oil lamp cracks when touched with rhe brade of cold knife?why

Physics

2 answers:

Bezzdna [24]3 years ago

7 0

Answer:

The extreme difference between the hot chimney and the cold knife makes the chimney expand and contract so quickly it cracks.

Explanation:

Hope this helped!

Fiesta28 [93]3 years ago

6 0

Answer:

When a blade of cold knife is touched to hot glass chimney there is a sudden drop of temperature on the spot where the blade touches. As a result it cracks.

Explanation:

When a blade of cold knife is touched to hot glass chimney there is a sudden drop of temperature on the spot where the blade touches. This decrease in temperature makes the glass to contract. The stress developed on the site of contraction is responsible for the cracking of the glass chimney.

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Narysuj wykres zależności szybkości od czasu i drogi od czasu jeśli ciało porusza się ruchem jednostajnym z szybkością 45 m/s.

murzikaleks [220]

Lett me come back imma translate this... and then ill come to help

7 0

3 years ago

A physics professor demonstrates the Doppler effect by tying a 600 Hz sound generator to a 1.0-m-long rope and whirling it aroun

cluponka [151]

Answer:Highest frequency =618.89Hz

Lowest frequency=582.22Hz

Explanation:

The linear velocity of a sound generator is related to angular velocity and is given as

Vs = rω where

r = the radius of circular path = 1.0 m

ω is the angular velocity of the sound generator. = 100 rpm

1 rev/min = 0.10472 rad/s

100rpm =10.472 rad/ s

Vs = rω

= 1m x 10.472rad/ s= 10.472m/s

A) Highest frequency heard by a student in the classroom = Maximum frequency. Using the Doppler effect formulae,

f max = (v/ v-vs) fs

Where , v is the speed of the sound in air at 20 degrees celcius =

343 metres per second

vs is the linear velocity of the sound generator=10.472m/s

fs is the frequency of the sound generator= 600 Hz

f max = (343/ 343 - 10.472) x 600

=343/332.528) x600

=618.89Hz

B) Lowest frequency heard by a student in the classroom = Minimum frequency

f min = (v/ v+vs) fs

(343/ 343 + 10.472) x 600

=343/353.472) x 600

=582.22hz

5 0

3 years ago

Consider a container of oxygen gas at a temperature of 23°C that is 1.00 m tall. Compare the gravitational potential energy of a

Sergio039 [100]

Answer:

Yes, it is reasonable to neglect it.

Explanation:

Hello,

In this case, a single molecule of oxygen weights 32 g (diatomic oxygen) thus, the mass of kilograms is (consider Avogadro's number):

$m=1molec*\frac{1mol}{6.022x10^{23}molec} *\frac{32g}{1mol}*\frac{1kg}{1000g}=5.31x10^{-26}kg$

After that, we compute the potential energy 1.00 m above the reference point:

$U=mhg=5.31x10^{-26}kg*1.00m*9.8\frac{m}{s^2}=5.2x10^{-25}J$

Then, we compute the average kinetic energy at the specified temperature:

$K=\frac{3}{2}\frac{R}{Na}T$

Whereas $N_A$ stands for the Avogadro's number for which we have:

$K=\frac{3}{2} \frac{8.314\frac{J}{mol*K}}{6.022x10^{23}/mol}*(23+273)K\\ \\K=6.13x10^{-21}J$

In such a way, since the average kinetic energy energy is about 12000 times higher than the potential energy, it turns out reasonable to neglect the potential energy.

Regards.

8 0

4 years ago

Value of g is independent of

Margaret [11]

The lord of the greeks answer d

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3 years ago

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Research has shown that the electrons orbit the nucleus in circular motions as shown on the classic Bohr model.

Stels [109]

Research has shown that the electrons orbit the nucleus in circular motions as shown on the classic Bohr model. FALSE