Question

a gun fires a bullet at a speed of 140 m/s. if the bullet is to hit a target at the same level as the gun and at 1 km distance, the angle of projection may be

Answer 1

R = u^2 sin(2x)/g
sin(2x) = Rg/u^2
sin(2x) = 1000 * 10 / (140)^2
sin(2x) = 10000 / 19600
sin(2x) = 100/196
sin(2x) ≈ 0.5
sin(2x) = sin30
x = 15°

Angle of projection is nearly 15°

Answer 2

Answer:

R = u^2 sin(2x)/g

sin(2x) = Rg/u^2

sin(2x) = 1000 * 10 / (140)^2

sin(2x) = 10000 / 19600

sin(2x) = 100/196

sin(2x) ≈ 0.5

sin(2x) = sin30

x = 15

Angle of projection is nearly 15 degree or 75 degree