Air molecules in a warm room (27°C = 300 K)typically have speeds of about 500 m/s (1,100 mph). Why is it that we are unaware of these fast-moving particles continuously colliding with our bodies?which is correct?
The size of an air molecule is extremely small, so its momentum and kinetic energy are not efficiently transferred to our bodies when the collisions with a human body occur.The density of the warm air is so low that the air molecules tend to miss our bodies.Because the air molecules are everywhere around us they constantly collide with our bodies from all directions. The effect of these collisions tend to cancel out.The mass of an air molecule is so miniscule that its momentum and kinetic energy are too small to be evident in the collision with a human body.