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ramyani (2963)

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Olaaa!! Perrrfect answer. 501  [730 rates]

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Method 1




Lets us visualize a situation in which a projectile is fired at a height 1m above the ground and an angle 53 degree to the horizontal ( I can't draw. How u draw ?).



The coordinates of the any arbitrary point be (x, y ).

then,

x = ( horizontal component of vel) * time = u cos 53 * t ---------------(1)



y = (vertical component of vel ) * time --gt2  / 2 = ( u sin 53) *t --gt2  / 2  -----(2)



Putting the value of t from (1) in (2)



y = ( u sin 53) *( x / u cos 53 ) -  g ( x / u cos 53 )2  / 2

 

or, y = x tan 53  ( gx2 ) / 2 u2 cos2  (53)

 

             Now comes the crux of the problem.

 

Let the ball strikes the p th step.

Then

 

y =  p * 1 m -- 1m = p - 1

 

x = 110 + y

 

y =  ( 110 + y) tan 53  [ g (110 + y )2  ] /  2 u2  cos2  (53)

 

y =  ( 110 + y) tan 53  [ 10 ( 12100 + 220y + y2 )  ] / 2 * 35 * 35 * cos2   (53)

 

y comes out 5

 

now

 p - 1 = 5

or, p = 6

 

Ans:  sixth step if the ball is hit 1m  above ground.





method 2.



cvramana (609) sir )








Since the initial height is 1m and initial distance is 110m use the formula

 

n - 1 = (n + 110) tan - g (n + 110)2 / 2 (35)2 cos2, where n is the no. of the step on which it lands. There is a possibility for you to get a non-integer answer. If you get something like 3.4, the answer must be 4. If you get 7.1 the answer must be 8 and so on.


it is not important where u stand, but in which direction u are moving
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