The speed of a moving body decreased by 3 times. Moreover, its kinetic energy

Kinetic energy is proportional to the mass of the body and the square of its speed. Therefore, with a decrease in the speed of the body by 3 times, its kinetic energy decreases by 9 times.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.