At the height of 80 m , an aeroplane is moving with 150 m / s . A bomb is dropped from it so as to hit a target . At what distance from the target should the bomb be dropped ? ( g = 10 m / s ) .

1 ) At the height of 80 m , an aeroplane is moving with 150 m / s .  A bomb is dropped from it so as to hit a target .  At what distance from the target should the bomb be dropped ?   ( g = 10 m / s ) .

Choose single option from these following : -

A ) 230 m ,                                                 B ) 460 m ,

C ) 600 m ,                                                D ) None of these ,

Correct Answer : -   C ) 600 m ,

Solution : -

As plane is moving with 150 m / s ,  so  bomb initial horizontal velocity will become 150 m / s .

So it takes time to cover distance Y  ,  as it takes time to cover height h .

So , height is 80 m , so distance is 80 m .

We use formula here ,  2^nd equation of motion  : -

S = vit  +  (1/2) a t²  ,

80  =  0  +  (1/2) (10) t²  ,         ∴  a = 10 m / s2 .    

t² = 16 ,

t = 4 sec   .   So at that time bomb will touches the ground .

So ,  now we can find the distance ;

v  =  d / t  =  Y / t  .

Y  =  v x t  =  150 x 4  =  600 m  ,  Answer .

So at that distance the bomb should dropped .

 

2 ) A plane is flying horizontally at a height of 200 m with a speed of 200 m / s .  When bomb is released from it ,  find 

( i ) : -  the time taken by bomb to reach the ground ?

( ii ) : -  the velocity with which the bomb hits the target and the distance of target from where the bomb is dropped ?  ( g = 10 m / s2 ) .

Solution : -