There have been more than 2 dozen DIFFERENT 20mm cannon (search 20mm Wikipedia for examples). These used different shells, and had different barrel lengths, and so have different muzzle velocities. The 20mm used by the US and Allies during WW II had a muzzle velocity of ABOUT 2800 feet per second.
A stream with a velocity of 20 cm/s can transport particles up to fine sand size (0.0625 - 2 mm). Larger particles such as gravel and boulders would require a faster flow velocity to be transported.
0.001. because a micron is 1000 times smaller than a millimetre
A 5.56 mm bullet typically travels at speeds ranging from around 2,500 feet per second (fps) to over 3,000 fps, depending on the specific load and barrel length. This velocity allows the bullet to maintain stability and accuracy over longer distances. The high velocity also contributes to the bullet's effectiveness in terms of terminal ballistics, making it a popular choice for military and civilian firearms.
You do not mention which 9 mm cartridge you are asking about. As the 9mm Luger (parabellum) is the most popular handgun load in the world, I assume this is the one? The maximum listed range is about 2200 metres. Actual distance will vary depending on the grain weight of the bullet (for the 9mm luger, from 100 to 147), barell length, and other factors.
"ncm" is not recognised as a measurement unit for length. There are nm and cm which are different units.
A 90 mm rifled cannon because the inside is grooved.
To get the kinetic energy of an object you need both mass and velocity. As it stands it can't be answered, as "mm" isn't a recognized unit of velocity
The Mitsubishi A6M Zero had two 20 mm cannon and two 7.7 mm (.303 in) machine guns .
According to what I found, F-14 Tomcats were outfitted with one Vulcan 20 mm cannon. So it shoots 20 mm bullets. This cannon is a 6 barrel rotary 'gatling gun' type weapon, which can fire over 6000 rounds per minute. See related link.
A stream with a velocity of 20 cm/s can transport particles up to fine sand size (0.0625 - 2 mm). Larger particles such as gravel and boulders would require a faster flow velocity to be transported.
20 mm should still be 20 mm!
None but 20 mm = 2 cm
Most early Spitfires carried the Browning .303, a modification of the US Browning 30 cal. Later models carried 20 mm cannon instead.
20 mm - 0.2mm = 19.8
"Powerful" is somewhat of a subective term, but the answer is yes. 5.56 is a rifle cartridge and 9mm, assuming you mean 9mm parabellum, is a handgun cartridge. Under normal circumstances, bullets fired from rifles will have more velocity and more muzzle energy than bullets fired from handguns.
20 mm cannons.
Circumference = 20*pi mm