A stone is projected from a point on the ground in such a direction so as to hit a bird on the top of a telegraph post of height 'h' and then attain the max. height'2h' above the ground. If at an instant of projection the bird were to fly horizontally with uniform speed find the ratio between the horizontal velocity of the bird and the stone if the stone still hits the bird.
32/(√2+1) =ans???
sry abt calc errors ....
the only thing u need is
h = vt - 1/2gt^2 .......
solve and get two val of t ...... t1,t2 .....
1 is the time in which proj is goin upward and the other its goin downward !!!!!!
thats more than sufficient a hint i feel!!!!!!!!!!!!!!!
3okie if u want full soln/
let v = vertical velocity of projectile ....
v2/2g=2h ...... v2=4gh///
now
h= vt-1/2gt2
or we get
t = v ±√v2-2gh/g
time the bird had to fly the distance =
v+√v2-2gh/g
√4gh + √2gh/g
time the ball had
2√2gh/g
therefore...
let u1=ball horizontal vel .... u2 = bird vel
u2√4gh + √2gh/g = u1 2√2gh/g
u2/u1 = 2√2/2+√2 = 2/(√2 +1)
hope u understood ...............