Answer:
<u>Conventions used in SI to indicate units are as follows:</u>
- Only singular form of units are used. for example: use kg and not kgs.
- Do not use full stop after the abbreviations of any unit. for example: do not use kg. or cm.
- Use one space between last numeric digit and SI unit. for example: 10 cm, 9 km.
- Symbols and words should not be mixed. for example: use Kilogram per cubic and not kilogram/m3.
- While writing numerals, only the symbols of the units should be written. for example: use 10 cm and not Ten cm.
- Units named after a scientist should be written in small letters. for example: newton, henry.
- Degree sign should not be used when the kelvin unit is used. for exmaple: use 37° and not 37°k
Earth's magnetic field is the force acting on the compass needle to cause it to point northeast.
Answer electrons are negative. Protons are positive, and neutrons are neutral
Answer:
Sound waves are produced when something vibrates.
Explanation:
The vibrating body causes the medium (water, air, etc.) Vibrations in air are called traveling longitudinal waves, which we can hear. Sound waves consist of areas of high and low pressure called compressions and rarefactions, respectively.
Sorry if this if wrong
Answer:
B) 1.5 m/s
Explanation:
The apparent frequency will be enhanced due to Doppler effect
If f be the apparent frequency , F be the real frequency , V be the velocity of sound and v be the velocity of approaching submarine then f is given by
f = F \frac{V+v}{V-v}\\
\frac{f}{F} =\frac{V+v}{V-v}\\
\frac{f}{F}-1 =\frac{V+v}{V-v}-1\\
\Delta f = \frac{2vf}{V-v}\\
200=\frac{2\times v\times 100\times 1000}{1482-v}\\
v=1.48 m/s
