A rocket is fired at a speed of 70.0 m/s from ground level, at an angle of 40.0 ° above the horizontal. The rocket is fired toward an 14.0-m high wall, which is located 21.0 m away. The rocket attains its launch speed in a negligibly short period of time, after which its engines shut down and the rocket coasts. By how much does the rocket clear the top of the wall? I keep getting 1.64 m but its not the correct answer

Answer 1

t=x/v(0x) = x/v(0) •cosα=
=21/70•cos40°=0.39 s.
h=v(oy) •t - gt²/2 =
=v(o) •sinα•t - gt²/2=
=70•sin40°•0.39 – 9.8•0.39²/2 =16.8 m
Δh=16.8-14 = 2.8 m.

Answer 2

apparently that is incorrect as well according to the assignment program:/