IIT JEE , AIEEE Forum - Physics , Mechanics

ramyani

You wrote " dont tell me the answer..just prompt me..."
OK
There r 2 components of velocity----x component ( or horizontal component ) and y component ( or vertical component ). u sin

and u cos

.

is given 42 degree.

    Now rock lands 9.5m below the initial level. So u know initial y co-ordinate--9.5. The final y co-ordinate is zero on the ground.
                Use y = ( u sin

) t + 1 / 2 ( a) t² { what is accln here ?? }
So u can find t.
In this time the rock travels horizontally with horizontal component of velocity. And remember in projectile , horizontal component of velocity remains same.
So u can find the width of river ( horizontal distance )
the next is velocity at impact. try.

p.s. why hate physics ?

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