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## Homework Statement

There is a projectile which is launched at point "o" and land at "B".It was thrown with 20m/s with angle of 53 degree.Take g=10 m/s^2 sin theta=0.8 and cos theta=0.6

Find the time at which magnitude of x component of velocity of projectile is twice the magnitude of y component of velocity.

## Homework Equations

v sub x =u sub x +a sub x t

u sub x=initial velocity in x-direction i.e u cos theta =16 m/s

v sub x =velocity in x direction at time t.

v sub y =velocity in y direction at time t

v sub y =u sin theta +(- 10 t)

## The Attempt at a Solution

v sub x=2 (u sin theta +(- 10 t)

but v sub x=u cos theta (as acceleration in x i.e horizontal direction is zero.

so,u cos theta =2 (u sin theta - 10 t)

putting given values give

t=1 sec.

But in book two answer are given

t=1 sec

and t=2.2 sec.

How I can get t=2.2 s ?