Height of cliff is 66.43 meter.
Step-by-step explanation:
Consider the horizontal motion of shell,
We have equation of motion s = ut + 0.5 at²
Initial velocity, u = 1770 m/s
Acceleration, a = 0 m/s²
Displacement, s = 6520 m
Substituting
s = ut + 0.5 at²
6520 = 1770 x t + 0.5 x 0 xt²
t = 3.68 s
Time of flight of shell = 3.68 s.
Now consider the vertical motion of shell,
We have equation of motion s = ut + 0.5 at²
Initial velocity, u = 0 m/s
Acceleration, a = 9.81 m/s²
Time, t = 3.68 s
Substituting
s = ut + 0.5 at²
s = 0 x 3.68 + 0.5 x 9.81 x 3.68²
s = 66.43 m
Height of cliff is 66.43 meter.