1800-150-456-789
FlagBACK
Flag Mechanics> a stone is projected from the ground in s...
question mark

a stone is projected from the ground in such a direction so as to hit a bird sitting on the top of a telegraph post of height h and attains a maximum height of 2h above the ground. if at the instant of projection the bird were to fly away horizontally with the uniform speed. then find the ratio between the horizontal velocity of the bird and the stone if the stone hits the bird while descending

Sparsh Goel , 9 Years ago
Grade 11
anser 3 Answers
varun

Last Activity: 9 Years ago

for heigt of maximum by projectile will be         R tan theta =4H and......
 R  :  radius of projectile
H:  height of projectile
 

Piyush Kumar Behera

Last Activity: 7 Years ago

Let Vy be the vertical component of the stone's velocity and Vx be it's horizontal velocity.

Max height = 2H = (Vy^2)/2g

Vy^2 = 4gH

Now, the time at which the stone reaches height H. There will be two such times. Let them be T and T', where T > T'.

H = (Vy)t - g(t^2)/2

Solutions of this are T, T'.

T = Vy + sqrt[Vy^2 - 2gH]/g

We need T - T' for the time between the 2 heights.

T - T' = 2sqrt{Vy^2 - 2gH}/g

Finally, (velocity of bird)/(Vx) = (T - T')/T = 2/[(sqrt2) + 1]

 

Aakarsh

Last Activity: 4 Years ago

Time taken to reach at height '2h' from ground is equivalent to time taken to reach on ground from max. height.
So time taken by the stone to reach at height 'h'=
                t=√[2.(2h/g)] +_ √(2h/g)
                t1=(2-√2)√(h/g)
                t2=(2+√2)√(h/g)
Let velocity of bird be v'
Let horizontal component of velocity of stone be v
                v'.t2 = v(t2-t1)
                v'/v = 2/(√2+1).
 
 
 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...

Other Related Questions on mechanics

question mark
A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mmat the free end, where a small mass of 2 g is positioned. determine(i) The velocity of the end when passing through the zero position(ii) The acceleration at maximum displacement(iii) The maximum kinetic energy of the mass
mechanics
2 Answers Available

Last Activity: 2 Years ago

question mark
An object of mass m = 0.25 kg oscillates in a fluid at the end of a vertical spring of springconstant kH = 85 N/m, see Fig.1. The effect of the fluid resistance is governed by thedamping constant b = 0.07kg/s.(i) Find the period of the damped oscillation.(ii) By what percentage does the amplitude of the oscillation decrease in each cycle?
mechanics
1 Answer Available

Last Activity: 2 Years ago

question mark
If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0
mechanics
1 Answer Available

Last Activity: 2 Years ago

question mark
A particle is traveling in a circle of radius R =2.5m and with an angular velocity of 10 rad/s. What is the centripetal acceleration of the particle? The particle begins to slow down with an angular acceleration of -1 rad/s2. After 5 seconds, what is the centripetal acceleration and the tangential acceleration fo the particle?
mechanics
1 Answer Available

Last Activity: 2 Years ago

question mark
If the acceleration of block A is 5 m/s^2Find the acceleration of block B
mechanics
1 Answer Available

Last Activity: 2 Years ago