A bullet weighing 9g flies out of the rifle barrel at a speed of 800m / s. What is its kinetic energy?

Kinetic energy is the energy of body movement. It depends on body weight and speed. You can find the value of kinetic energy using the formula:
Ek = m * v ^ 2/2, where
m is body weight.
v is the speed of the body.
In the condition of the problem, all the necessary values for its solution are given.
Let’s substitute the values into the formula:
Ek = 0.009 kg * 800 ^ 2 m / s / 2 = 0.009 kg * 640,000 m ^ 2 / s ^ 2/2 = 5760 kg m ^ 2 / s ^ 2 = 5760 J
The unit of measurement of kinetic energy is joule, therefore, before the decision, the value of grams was converted to kilograms.
Answer: 5760 J.