Question

1) Horizontal is same for angle of projection θ and (90-θ).
2) a shell is fired at an angle 30° to the horizontal with a velocity 196 m/s. Find the total time of flight, horizontal range and maximum  height attained?

Answer 1

we know that
range=(u)square sin 2tita /g
then according to question,
range=(196)(196)( sin 2(30))/10  we know g=10
        =38416 (root3)/2 /10
       =38416(1.7320)/20     
 t=2u sin(tita)/g
 =2(196)sin(30)/10
 =392(1/2) /10
h max=(u) square( sin)
square (tita)/2g 
   =(196)square (sin)square(30)/2(10)
  =38416(1/2)(1/2)/20

Answer 2

angle of projection (α) = 30
velocity (u) = 196 m/s

total time of flight = $\frac{2usin( \alpha )}{g} = \frac{2*196*sin(30)}{9.8} =\frac{2*196*0.5}{9.8} =20s$

horizontal range = $\frac{ u^{2}*sin(2 \alpha ) }{g} = \frac{ 196^{2}*sin(60) }{9.8} = \frac{ 196^{2}* \frac{ \sqrt{3} }{2} }{9.8} =3394.82m$

maximum height = $\frac{ (u*sin(30))^{2} }{2*g} = \frac{ (196*0.5)^{2} }{2*9.8} = \frac{ 98^{2} }{19.6} =490m$