question_answer

A foot ball kicked vertically up reaches a height 'h' and comes down to the starting point in 4seconds. Find the value of h.

Answer:

\[t=\sqrt{\frac{2h}{g}}\,\,or\,\,{{t}^{2}}=\frac{2h}{g}\,\,or\,\,h=\frac{1}{2}g{{t}^{2}}\] or \[h=\frac{1}{2}\times 9.8\times 2\times 2=9.8\,m\] Note that we are to consider only the time taken for upward journey and not the total time.