 Hi and welcome to the session. Let us discuss the following question. The question says a body falls freely from the top of a tower. It covers 5 by 9 of the whole distance in the last second. Find the height of the tower and the total time taken by the body to fall down. Now begin with the solution. Let the time of fall of the body be t seconds over the edge meters. Body in tth second will be into 2t minus 5 is equal to ut plus half dt square. Now as the body falls freely from the top of the tower, so this means initial velocity is equal to zero and we have assumed height of the tower as edge meter. So this means s that is the distance covered by the body is edge meter. By substituting zero in place of u and edge in place of s, we get 1 by 2 gt square. This equation is 1 and this as 2. Body covers 5 by 9 of the whole distance in the last second. So that means 2g into 2t minus 1 and edge is 1 by 2 gt square. This implies t minus 1 is equal to 5 by 9 t square. t minus 9 is equal to 5t square. This implies t square minus 18t plus 9 is equal to zero. This implies minus 15t minus 3t plus 9 is equal to zero. This implies 5t into t minus 3 minus 3 into t minus 3 is equal to zero. If t minus 3 into t minus 3 is equal to zero, 5t minus zero or t minus 3 is equal to zero. So this implies t is equal to 3 by 5 or t is equal to 3. Now t cannot be t of g and t, we get 1 equal to 45 meters.