What percent of air by volume is nitrogen

The table below lists the characteristics of various stars.

Dafna1 [17]

Answer:

d is the answer

Explanation:

4 0

3 years ago

A man strikes one end of a thin rod with a hammer. The speed of sound in the rod is 15 times the speed of sound in air. A woman,

lina2011 [118]

Answer:

44.1 m

Explanation:

<u>Given:</u>

$V_a$ = speed of sound in air = 343 m/s
$V_r$ = speed of sound in the rod = $15V_a$
$\Delta t$ = times interval between the hearing the sound twice = 0.12 s

<u>Assumptions:</u>

$l$ = length of the rod
$t$ = time taken by the sound to travel through the rod
$T$ = time taken by the sound to travel to through air to the same point = $t+\Delta t = t+0.12\ s$

We know that the distance traveled by the sound in a particular medium is equal to the product of the speed of sound in that medium and the time taken.

For traveling sound through the rod, we have

$l=V_r t\\\Rightarrow t = \dfrac{l}{V_r}$ ..........eqn(1)

For traveling sound through the air to the women ear for traveling the same distance, we have

$l=V_aT\\\Rightarrow l=V_a(t+0.12)\\\Rightarrow l=V_a(\dfrac{l}{V_r}+0.12)\,\,\,\,\,\,(\textrm{From eqn (1)})\\\Rightarrow l=V_a(\dfrac{l}{15V_a}+0.12)\\\Rightarrow l=\dfrac{l}{15}+0.12V_a\\\Rightarrow l-\dfrac{l}{15}=0.12V_a\\\Rightarrow \dfrac{14l}{15}=0.12V_a\\\Rightarrow l = \dfrac{15}{14}\times 0.12V_a\\\Rightarrow l = \dfrac{15}{14}\times 0.12\times 343\\\Rightarrow l = \dfrac{15}{14}\times 0.12\times 343\\\Rightarrow l = 44.1\ m$

Hence, the length of the rod is 44.1 m.

4 0

3 years ago

The picture below shows a person swinging a yo-yo in a circle. Which vector shows the velocity of the yo-yo at this moment?

igor_vitrenko [27]

C, at this moment it is directly 90 degrees to the right and is only travelling downwards

6 0

3 years ago

Compare the roles of mitochondria and chloroplasts in plant and animal cells

Ivahew [28]

Mitochondria help take energy from sugar or glucose and convert it into a simpler form, called ATP, that the cell can more easily use. This process is called cellular respiration, and the mitochondria plays a central role in it.Mitochondria are composed of two membranes.An outer membrane covers the organelle like a skin, protecting it.An inner membrane, that is folded over again and again to create a layered structure called crista, which is studded with proteins. The fluid inside these folds is called the matrix.Chloroplasts are very similar to mitochondria, but are found only in the cells of plants and some algae. Like mitochondria, chloroplasts produce food for their cells. Chloroplasts help turn sunlight into food that can be used by the cell, a process known as photosynthesis.

5 0

3 years ago

An electromagnet is strong enough to lift 200 kg of mass. If you double the number of turns of wire around the core and triple t

VLD [36.1K]

Answer:1200 kg

Explanation:

Given

Electromagnet can lift a mass of $200\ kg$

Magnetic force necessary to hold mass is proportional to Magnetic field

and magnetic field (B) is proportional to NIA

where N=no of turns

I=current in the magnet

A=area of cross-section

When we double the no of turns and triple the current then

N becomes 2 N

I becomes 3 I

therefore magnetic field becomes 6 times

Thus magnetic force becomes 6 times and we can say that electromagnet can hold the 6 times of given weight

i.e. $6\times 200=1200\ kg$

4 0

3 years ago

What percent of air by volume is nitrogen​

What percent of air by volume is nitrogen