Really interesting iitjee problem

JEE Main 2015 Discussion Forum › Mechanics questions › Really interesting iitjee problem

A train is moving along a straight line with a constant acceleration a. A boy standing in the train throws a ball forward at an angle of 60Â° to the horizontal. The boy has to move forward by 1.15m inside the train to catch the ball back at the initial height. The acceleration of the train in ms^-2 is?

#Physics #Mechanics

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2 Answers

996

Swarna Kamal Dhyawala ·2013-02-23 19:16:03

s=ut+1/2at²
0=usin60Â°t + 1/2*10t² (vertically)
after substituting the value of u=10m/s and a =10m/s²
we get t =âˆš3 sec
1.15 = 10cos60Â°âˆš3 - 1/2*a*(âˆš3)² (horizontally)
a =5m/s²

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Soumyadeep Basu How do you get u = 10?
Upvote·0· Reply ·2013-02-23 22:50:59
Sourup Nag it was given u= 10, i forgot 2 mention that
Upvote·0· Reply ·2013-02-23 23:02:52
Swarna Kamal Dhyawala actually this some was done in class @soumyadeep
Upvote·0· Reply ·2013-02-23 23:08:44
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996

Swarna Kamal Dhyawala ·2013-02-23 19:02:36

the acceleration of train is 5m/s²

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