It is possible to project a particle with a given velocity in 2 possible ways so as to make it pass through a pt P at a distance r from the point of projection. The product of the times taken to reach this point in two possible ways is then proportional to
Options
1/r
r
r^3
1/(r)^2

Question

It is possible to project a particle with a given velocity in 2 possible ways so as to make it pass through a pt P at a distance r from the point of projection. The product of the times taken to reach this point in two possible ways is then proportional to 
Options
1/r
r
r^3
1/(r)^2

anonymous · Answer

range=u^2sin2@/g
time=2usin@/g
for complimentary angles we get the same range
like 30 and 60
so sin30=cos60
use these infos to proceed
i will help if u get stuck

anonymous · Answer

thanks a lot
now is this correct?
t*T=2u^2sin2@/g^2
so t*T/r=2/g
and t*T is proprtional to r??