Answer:


Explanation:
r = Radius = 2.7 cm
F = Force = 
A = Area = 
= Stress = 
E = Young's modulus = 
= Strain
= Original length = 67 cm
= Change in length
Young's modulus is given by

Strain is 
Strain is given by

The cylinder height decreases by 
Answer:
1⁺ ion
Explanation:
Metals in the first group on the periodic table will prefer to form 1⁺ ion. This is because the 1 valence electron in their orbital.
Most metals are electropositive and would prefer to lose electrons than to gain it.
Like all metals, the group 1 elements called the alkali metals would prefer to lose and electron.
On losing an electron the number of protons is then greater than the number of electrons. This leaves a net positive charge.
<u>Answer:</u>
<em>The average speed of the car is 66.9 km/h</em>
<u>Explanation:</u>
Here distance covered with the speed <em>57 km/h=7 km </em>
distance covered with the speed of <em>81 km/h=7 km</em>
<em>Average speed is equal to the ratio of total distance to the total time.
</em>
<em>total distance= 7 + 7= 14 km </em>
<em>
</em>
<em>time taken to cover the first 7 km= 7/57 h </em>
<em>time taken to cover the second part of the journey = 7/81 h
</em>
<em>average speed =
</em>
<u><em>Shortcut:
</em></u>
<em>When equal distances are covered with different speeds average speed=2 ab/(a+b) where a and b are the variable speeds in the phases.
</em>
1) 211m/s
2)240<span>°
3)759,600m or 759.6 km</span>
From the measured wavelength from diagram, the frequency of the sound is 6660 Hz.
<h3>What is the frequency of a wave?</h3>
The frequency of a wave is the number of complete oscillation per second completed by a wave.
Frequency is related to wavelength and speed by the following formula:
- Frequency = velocity/wavelength
Velocity of sound in air = 330 m/s
The measured wavelength = 5.0 cm = 0.05 m
Frequency = 330/0.05 = 6660 Hz
Therefore, based on the measured wavelength from diagram, the frequency of the sound is 6660 Hz.
Learn more about frequency of sound at: https://brainly.in/question/15373132
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