If masses of all molecules of a gas are halved and the speed doubled. Then the ratio of initial and final pressure is :

Explanation

`because P=(1)/(3)(M)/(V)v^(-2)=(1)/(3)(mn)/(V)v^(-2)`
`therefore (P_(1))/(P_(2))=(m_(1))/(m_(2))((barv_(1))/(barv_(2)))^(2)=((2m)/(m))((barv_(1)^(2))/(2barv_(2)^(2)))^(2)`
or `(P_(1))/(P_(2))=(2xx1)/(4)=(1)/(2)therefore (P_(1))/(P_(2))=(1)/(2)`