Question

Arifle shoots a bullet with a velcocity 400m/s at a samall target 400 m away. Teh height above the target at which the bullet must be aimed to hit the target is?

Answer 1

Hello.... ☺

If the angle of shooting is α...!!!!

time taken to reach target:-

t=400➗(400✖ cosα)
  =1➗cosα

vertical fall in this time = 1➗2 ✖g✖ t²
                                  = 1/2 ✖9.8 ✖ 1➗cos²α
tanα= vertical fall/distance
       =(1/2 ✖9.8✖1➗cos²α)➗400
sinα ✖cos α =9.8➗800
sin2α =2✖9.8/800
          =0.0245

2α= sin inverse of 0.0245
    =1.404
α=0.702
tanα =0.01225

height of aim = tanα ✖400
                    =0.01225✖400
                    =4.9 meters above horizontal.......


thank you ☺