Question

A body is projected at an angle of 30degree to the horizontal with a velocity of 150metre per seconds.Calculate the time it takes to reach the greatest height,take g=10metre per seconds square and neglect air resistance.

Answer 1

v = Vi - g t
here Vi = 150 sin 30 = 75 m/s

at top v = 0
0 = 75 - 10 t
solve for t at top
t = 7.5 seconds

then if they ask for the height
h = (1/2) g t^2 to fall from top
= 5 * (7.5)^2

then if they ask for range
u = 150 cos 30
range = u t = 150 cos 30 * 7.5 * 2
the 2 is because t is only the upward half of the parabola

Answer 2

Another answer

Answer 3

Thanks it is very explanatory