A ball is thrown with a speed of 100m/s attain the height of 150m, (take g=10m/s^2). calculate... (i)Time of flight (ii)Angle of projection (iii)Range???

Answer 1

u = speed in horizontal direction until crash into ground
v = speed up
Vi = initial speed up
A = throw angle up from horizontal in degrees
Vertical problem:
v = Vi - 10 t
at top, v = 0
so 0 = Vi - 10 t
t = Vi/10 ( time to top is t )
h = 0 + Vi t - 5 t^2 (h is height, 5 is g/2)
then at top when t = Vi/10 :
h = Vi (Vi/10) - 5 Vi^2/10^2 = Vi^2/20 at top
so
150 = Vi^2 / 20
Vi^2 = 3000
Vi = 55 m/s close enough
now geometry
tan A = Vi/100 = 55/100 = .55
so A = 29 degrees
u = 55 cos 29 = 48 m/s
time at u = twice time up = 2 (55/10) = 11 seconds in the air at horizontal speed 48
48 * 11 = 530 m

check my arithmetic, working fast. Have fun.

Answer 2

By the way, you threw a ball up 150 meters? You belong in the major leagues. I suspect that may be why it went over 5 football fields horizontally (or else I made serious arithmetic errors.)

Answer 3

224 miles/hour = 100 meters/second :) according to my search in the box above.