A physics teacher explains to his students in class, the subject of motion under gravity. When a body is project upwards from the ground with a certain velicity u, the velocity goes on decreasing at a constant rate due to gravitational pill of earth. At a certain height, this velocity becomes zero. the body cannot rise futher. from this maximum height, the body begins to fall and its velocity goes on increasing at the same constant rate due to gravitational pull of earth. the body would strike the ground with exactly the same velocity `(v=u)`, with which it was thrown initially. this is on the assumption that resistance due to air is zero,either way.
Read the above passage and answer the following quetion:
(i) why is velocity of body on striking the ground the same as intial velocity of projection of the body?
(ii) Does the body take same time to fall to ground as the time it takes to reach the maximum height?
(iii) What value of life of life do you learn from this breif study ?

Explanation

(i) The two velocities are equale in accordance with the principal of conservation of energy.During the upward journey,kinetic energy of the body is converted into its potential energy. And during the downward journey of the body, potential energy is converted back into the same kinetic energy. of course,we assume that there are no stray losses of energy.
(i) Yes, time taken to go from ground to the maximum height.
(iii) From this breif study, we learn that output can at the most be equal to input, i.e., the degree of our succes is always commensurate with our efforts. we reap what we harvest. the degree of sweetness is determind by the amount of sugar we put in.