Correct Answer - c
`v^(2)=u^(2)-2gh or u^(2)=v^(2)+2gh`
or `u_(x)^(2)+u_(y)^(2)=v_(x)^(2)+v_(y)^(2)+2gh`
As `v_(x)=u_(x), u_(y)^(2)=v_(y)^(2)+2gh`
or `u_(y)^(2)=(2)^(2)+2xx10xx0.4=12`
`u_(y)=sqrt(12)=2sqrt(3)m//s`
`u_(x)=v_(x)=6m//s`
`tan theta=(u_(y))/(u_(x))=(2sqrt(3))/6=1/(sqrt(3))`
`theta=30^(@)`