Xiaoming's hometown is a demonstration site for building a new socialist countryside. Slides and other fitness equipment were newly installed in front of the village Committee. Xiao Ming observed that

Xiaoming's hometown is a demonstration site for building a new socialist countryside. Slides and other fitness equipment were newly installed in front of the village Committee. Xiao Ming observed that the height of the slide was about1.2m, 3. Answer: (1) children slide down the slide with acceleration, and their speed and kinetic energy increase; The height becomes smaller, so the gravitational potential energy becomes smaller and converted into kinetic energy.

(2) When children slide down the slide, mechanical energy is not conserved, because when they slide down, children overcome friction and do work, and part of mechanical energy is converted into internal energy.

(3) If the slideway is made too high and too long, the temperature of children's buttocks will rise due to friction, causing children's buttocks to be injured; The slide is too high and too long, and the child's initial gravitational potential energy is too large, which makes the kinetic energy of the child rushing down too large, which is easy to cause danger.