Grade 7IIT JEE Entrance Exam

A stone is drooped from the top of a tower travels 25 m in last second of its motion. If [g=10], height of the tower is

Shikhar

8 Years agoGrade 7

3 Answers

Soumya Ranjan Mohanty

8 Years ago

Dear student,We know distance travelled in nth second = u +(a/2)(2n-1)Here u=0, a=g and n = total time takenGiven distance travelled in last second = 25mSo 25= (10/2)(2n-1)=> 5=2n-1=> n=3 seconds = total time taken.height of tower= (1/2)*g*n^2= (1/2)*10*3*3=45 m.So height of tower is 45 m. [Ans]Thank you,Soumya Ranjan Mohanty.

rahul gurjar

8 Years ago

answere ,Dear student,We know distance travelled in nth second = u +(a/2)(2n-1)Here u=0, a=g and n = total time takenGiven distance travelled in last second = 25mSo 25= (10/2)(2n-1)=> 5=2n-1=> n=3 seconds = total time taken.height of tower= (1/2)*g*n^2= (1/2)*10*3*3=45 m.So height of tower is 45 m. [Ans]Thank you,Soumya Ranjan Mohanty.

sahil

7 Years ago

the

the answer is

,Dear student,We know distance travelled in nth second = u +(a/2)(2n-1)Here u=0, a=g and n = total time takenGiven distance travelled in last second = 25mSo 25= (10/2)(2n-1)=> 5=2n-1=> n=3 seconds = total time taken.height of tower= (1/2)*g*n^2= (1/2)*10*3*3=45 m.So height of tower is 45 m. [Ans]Thank you,Soumya Ranjan Mohanty.