MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 11
        
A stone is thrown in such a manner that it would just hit a bird at the top of a tree and afterwards reach a maximum height double that of the tree. If at the moment of throwing the stone the bird flies away horizontally with constant velocity ant the stone hits the bird after some time. The ratio of horizontal velocity of stone to that of the bird is 1/n +1/√n. Find 2n.
10 months ago

Answers : (1)

Arun
20399 Points
							
Dear Mithun
 
For the stone:  uy = vertical speed             ux = horizontal speed
Let the height of the tree = h           max height reached = 2h
=>  uy^2 = 2 (2h) g = 4 h g    --- (1)
Let the speed of the bird be v.
The stone and bird meet at height y = h, two times t1 and t2.
y =uy t - 1/2 g t²  
=> h = 2√(hg) t - 1/2 g t²
=> t1 = √(2h/g) * [√2 - 1]                 t2 = √(2 h/g) * [√2 + 1 ]
at t = t1, the stone travels a distance = ux * t1
at t = t2, the stone travels a distance = ux * t2 = ux * t1 + v * t2
so   ux / v = t2/(t2 - t1) = (√2 + 1)/2 = 1/√2   + 1/2
So  n = 2  and  2n = 4
 
Regards
Arun
10 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 110 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details