Question

A body is projected at such an angle that the horizontal range is three times the greatest height. If the range is 400metres, find:
A. the necessary velocity of the
projection
B. the time of flight. ( take g=10m/s)
PLEASE I NEED THE ANSWER AS FAST AS POSSIBLE

Answer 1

its greatest height: 400/3m

consider vertical motion: consider horizontal motion:

v^2=u^2+2gs v=s/t

u^2=2*10*400/3 v=400/5.16=77.5m/s

u=51.6m/s v=root(77.5^2+51.6^2)=93.1m/s

v=u+gt

0=u-10t

t=5.16s

so time=5.16s, velocity=93.1m/s