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Grade 12Mechanics

an elevator without a ceiling is asending up with the constant velocoty 5ms-1.a ball is projected upwards from the floor of the elevator. at the instant the floor of the elevator is at height of 50 m from the ground. the initiate speed of ball is 15ms-1 withrespect to the elevator.what is the time the ball strikes the floor of elevator?

Profile image of GUNAWA
7 Years agoGrade 12
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1 Answer

Profile image of Harshul
7 Years ago
There are 2 methods of solving this question
Through relative method and through the simple one
Relative method is easier and less time consuming
So , I am going to solve this question in that way.
 
We are given that relative velocity of ball with respect to the elevator is 15 m/s  
We know total time of travel of any object thrown up with velocity u is 2u/g .
 
So time taken by the object is 2*15/10 
(The value of g is taken as 10 for simplicity)
So time taken is 3 seconds