A projectile of `2 kg` has velocities `3 m//s` and `4 m//s` at two points during its flight in the uniform gravitational field of the earth. If these two velocities are `_|_` to each other then the minimum `KE` of the particle during its flight is

Explanation

`v_(1) cos alpha=v_(2) cos (90-alpha)`
`3 cos alpha=4 sin alpha`
`tan alpha=3/4`
`KE_(min)=1/2mv_(1)^(2)cos^(2) alpha`
`=1/(cancel(2))xx cancel(2)xx3^(2)xx(4/5)^(2) =(9xx16)/25=5.76J`