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A ball is thrown from a point with a speed V at an angle of projection θ . From the same point and at the same instant, a person starts running with a constant speed V/2 to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection?

shiva S , 13 Years ago
Grade 11
anser 5 Answers
upender surepally

Man will catch the ball if the horizontal component of velocity becomes equal to the constant speed
of man i.e. θ=600

ApprovedApproved
Last Activity: 13 Years ago
Dhiraj Bhakta

horizontal distance covered by the ball= horizontal range= (hope u know the formula) R=[V2sin2(theta)]/g

time taken by the ball to reach the ground=T=2Vsin(theta)/g

note;] remember that time taken by the person to reach the spot and time taken

         by the ball to reach the ground(same spot)..is THE SAME;

time taken by the person to reach the spot= time taken by the ball..

    distance/speed (man)          =        2v sin theta/g  [ball]

    range/speed[man]               =             '''' '''' 

   ( V2sin 2 theta/g) / v/2        =              '''' ''''

       things cancel out in the equation and finally u get     sin (theta) = sin 2 (theta)                                                          

this can happen if theta = 00 ...............................which is not possible

...therefore  2 theta= 180-theta.........by trigonometry

                    3 theta = 180           =====>theta=600Wink

 

                                                            

Last Activity: 13 Years ago
Yashdeep singh
 A ball is thrown from a point with a speed V  at an angle of projection  θ . From the same point and  at the same instant, a person starts running with a constant speed V/2 to catch the ball. Will the  person be able to catch the ball? If yes, what should be the angle of projection?
Last Activity: 7 Years ago
riya
Yes, the person will be able to catch it at theta=60 degree.horizontal component of velocity becomes equal to speed.
Last Activity: 6 Years ago
Kushagra Madhukar
Dear student,
Please find the solution to your problem.
 
For the boy to catch the ball, he must travel the range of projectile(ball) in the same time as the time of projectile.
Now, there is no horizontal direction acceleration.
Hence, vcosθ x T = v/2 x T
or, cosθ = ½
or, θ = 60o
Hence he will be able to catch the ball only when the angle of projection is 60o
 
Thanks and regards,
Kushagra
Last Activity: 5 Years ago
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