# Pressure of an ideal gas

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• Created by: boggleme
• Created on: 03-12-14 16:29
• Pressure
• In a box...
• If particle velocities increase, the force at which they hit the wall at increases so pressure increases
• If the number of particles increases, the total force acting on the wall per second increases so pressure increases
• If volume decreases then the particles have less distance to travel before they collide with the wall again. The total force increases so pressure increases
• Particles travel in random directions but for simplicity it can be said that a third of all particles are travelling in any one dimension (x, y, z)
• pV=Nm*mean square speed/3
• root mean square speed is the speed of an average particle
• Assuming...
• gas contains a large number of particles
• particles move rapidly and randomly
• motion of particles follow Newton's laws
• collisions are perfectly elastic (no energy or momentum is lost)
• no attractive forces between particles
• any forces during collisions are instantaneous
• particles have a negligible volume compared to that of the container
• random walk assumes all particles start somewhere, move N steps in random directions and ends up somewhere else
• distance moved = the root of the number of steps taken