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3 years ago

Please answer this soon. Thank u.

Physics

1 answer:

vodomira [7]3 years ago

6 0

Answer:

The distance used to calculate the pressure of atmosphere is 75 cm.

Explanation:

Mercury barometer is used to find the pressure of the atmosphere where it is placed.
As shown in the figure, the barometer has an inverted tube where mercury has risen by 75 cm. This height is taken into count to measure the atmospheric pressure.
At the place with high pressure the mercury in the inverted tube will go very high and vice versa.
Hence to find the pressure we must note down the height of mercury that has risen the inverted tube.

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The energy generated by the sun travels to Earth as electromagnetic waves of varying lengths. Which statement describes an elect

Paha777 [63]

Answer: 4(45)

Explanation:

It’s not equal

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3 years ago

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In world war 1 , Multiple reflection was used in submarines. How multiple reflection works and helps in such situation?

prisoha [69]

Answer:

Submarines use a device called Periscope that uses the concept of multiple reflections and help us see objects above the water surface.

Explanation:

When a light ray falls on a reflecting surface like a mirror, it gets reflected. In multiple reflections, the incident light ray is made to reflect multiple times by arranging the reflecting surfaces in different ways.

In submarines, we use Periscope, which is a long tube like structure. The long tube is bent at ends. It uses two simple mirrors which are placed parallel to each other at an angle of 45 degrees. The light from one mirror gets reflected to the other mirror, thus causing a multiple reflection.

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3 years ago

An electric current in a metal consists of moving

Alik [6]

The answer would be (A) Protons

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3 years ago

A rope passes over a fixed sheave with both ends hanging straight down. The coefficient of friction between the rope and sheave

Oliga [24]

Answer:3.51

Explanation:

Given

Coefficient of Friction $\mu =0.4$

Consider a small element at an angle \theta having an angle of $d\theta$

Normal Force $=T\times \frac{d\theta }{2}+(T+dT)\cdot \frac{d\theta }{2}$

$N=T\cdot d\theta$

Friction $f=\mu \times Normal\ Reaction$

$f=\mu \cdot N$

and $T+dT-T=f=\mu Td\theta$

$dT=\mu Td\theta$

$\frac{dT}{T}=\mu d\theta$

$\int_{T_2}^{T_1}\frac{dT}{T}=\int_{0}^{\pi }\mu d\theta$

$\frac{T_2}{T_1}=e^{\mu \pi}$

$\frac{T_2}{T_1}=e^{0.4\times \pi }$

$\frac{T_2}{T_1}==e^{1.256}$

$\frac{T_2}{T_1}=3.51$

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3 years ago

Why does helium have more spectral lines than hydrogen?

Lynna [10]

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3 years ago