Question 1176610
M=kr^2
0.5M=k(r1^2)
M=2k(r1^2)
so 2kr1^2=kr^2
2 r1^2=r^2
1/2=r1^2/r^2
sqrt(2)/2=r1/r2
it will decrease by 1-sqrt(2)/2 or (2-sqrt(2))/2
or about 29.3%
sqrt(2)=0.7071, which is the ratio of the smaller to the larger.