question_answer 48)

                  A man runs across the roof-top of a tall building and jumps horizontally with the hope of landing on the roof of the next building which is of a lower height then the first. If his speed is 9 m/s, the (horizontal) distance between the two buildings is 10 m and the height difference is 9 m, will he be able to land on the next building?                   (take \[g=10\,m/{{s}^{2}}\])                

Answer:

                  Time taken by the man to fall through a                 Height \[h(=9\,m),\,\,t\,=\,\sqrt{\frac{2h\,}{8}}\]                 \[=\,\sqrt{\frac{2\,\times \,9}{10\,}}\,\,=\,\sqrt{\frac{18}{10\,}}\]                 \[=\,1.34\,s.\]                 Horizontal distance travelled by man in                 \[1.34\,s=\,{{u}_{x}}\times t=9\times 1.34=12.06\,m\]                 Since, horizontal distance between two building is 10 m, so the man will be able to land on the next building.