If 10^(20) oxygen molecules per second strike 4cm^(2) of wall at an angle of 30^(@) with the normal when moving at a speed of 2xx10^(3)ms^(-1), find the pressure exerted on the wall. (mass of 1O_(2) atom = 2.67xx10^(-26)kg)

If 10^(20) oxygen molecules per second strike 4cm^(2) of wall at an an

1.	If 10^(20) oxygen molecules per second strike 4cm^(2) of wall at an angle of 30^(@) with the normal when moving at a speed of 2xx10^(3)ms^(-1), find the pressure exerted on the wall. (mass of 1O_(2) atom = 2.67xx10^(-26)kg)
Answer» Solution :Mass of `1O_(2)` atom `=2.67xx10^(-26)kg` Mass of `10^(20)O_(2)` atom = `2.67xx10^(-26)kg` `=26.72xx10^(-27)xx10^(20)` Momentum P = mv `=26.72xx10^(-7)xx8xx2xx10^(3)` `=427.5xx10^(-4)kgms^(-1)` COMPONENT of momentum normal to wall is `30^(@)` `=427.5xx10^(-4)xxcos30^(@)` `=427.5xx10^(-4)xx(SQRT(3))/(2)` `=370.2xx10^(-4)kgms^(-1)` PRESSURE = `(F)/(A) = ("Force (change in momentum)")/("area")` `=(370.2xx10^(-4))/(4xx10^(-4))` `P=92.55Nm^(-2)`