0

Guest

Courses New

A boy throws a ball horizontally with a speed of v°=12m/s from the Gandhi set bridge C of Patna in an effort to his the top surface AB of a truck traveling directly underneath the boy on the bridge.If the truck maintains a constant speed u=15m/s, and ball is projected at the instant B on the top of the truck appears at point C, determine the position s where the ball strikes the top of the truck.

A boy throws a ball horizontally with a speed of v°=12m/s from the Gandhi set bridge C of Patna in an effort to his the top surface AB of a truck traveling directly underneath the boy on the bridge.If the truck maintains a constant speed u=15m/s, and ball is projected at the instant B on the top of the truck appears at point C, determine the position s where the ball strikes the top of the truck.

Question Image
Grade:12

1 Answers

Arun
25750 Points
3 years ago
So, this is a very interesting question from the projectile motion
Now, 
Let us start from the basics,
Considering the boy was at rest while throwing the ball(not running or anything)
So, as the ball is thrown at an at an angle α the horizontal component of velocity will be vcosα  and the vertical component will be vsinα
(I am assuming Vo as asked in your question as v)
Let Vx= vcosα
then,
Vy=vsinα
Now, the range of projectile will be ( 2 × Vx × Vy )/g
which will be equal to,
R=( v² × sin2α )/g............... 1
And the time taken will be,
T=(2 × Vx)/g.................2
which will be equal to,
T=( 2× v sinα )/g
 
So, if he wants to catch the ball then the velocity with which he should run is..
=(Displacement)/(Time)
=Equation 1 divided by equation 2
=(sin2α)/(2sinα)
=(2 ×v× sinα ×cosα )/(2 sinα )
=v cosα
 
(This line after derivation in short means that horizontal component of the velocity should be the same)
(Since boy was running in horizontally only...so his velocity should be equal to horizontal component of the ball)
 

Think You Can Provide A Better Answer ?

Other Related Questions on Discuss with Askiitians Tutors

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More