1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A particle is projected from a point O with a velocity u in a direction making an angle α upward with the horizontal. After some time at point P it is moving at right angle with its initial direction of projection. The time of flight from O to P is

A

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is B When body projected with initial velocity →u by making angle α with the horizontal. Then after time t, (at point P) it’s direction is perpendicular to →u Magnitude of velocity at point P is given by v = u cot α (from sample problem no. 9) For vertical motion : Initial velocity (at point O) =u sin α Final velocity (at point P) =−v cos α=−u cot α cos α Time of flight (from point O to P) = t Applying first equation of motion v=u−gt −u cot α cos α=u sin α−gt∴ t=u sin α+u cot α cos αg=ug sin α[sin2 α+cos2 α]=u cosec αg

Suggest Corrections
15
Join BYJU'S Learning Program
Related Videos
Falling Balls in Disguise
PHYSICS
Watch in App
Join BYJU'S Learning Program