Question

solve this please as soon as possible

Answer 1

We know that R = U^2 Sin 2theta/g       -------------------- (1)

Given theta = 60.

Substitute theta in (1), we get 

R1 = u^2 sin 2 * 60/g

   = u^2 root 3/2g

   = u^2 root 3/2 g       ------------------- (2).


Given, theta = 30

Substitute theta in equation (1), we get

R2 = u^2 sin 2 * 30/g

   = u^2 sin 60/g

   = u^2 root 3/2 g       ---------------- (3).

Equation 2 can be written as u^2 root 3/2/g = u^2 root 3/2/10 = u^2 root 3/20.   ----- (4)

Equation3 can be written as u^2 root 3/2/g = u^2 root 3/2/10 = u^2 root 3/20.   ----- (5)

On solving (4) and (5) we get,

H1/H2 = u^2 root 3/20           u^2/80
              -------------------  =        ----------     =  1/3
              u^2 root 3/20           3u^2/80

H1 = H2/3.

Hence proved.

From (2) and (3), we can say that R1 = R2.

Hence proved.

Hope this helps!

Answer 2

as range is u²sin2 theta /g

and it remains same at angle theta and 90-theta.
further I Have tried on my notebook....