Using the information given in example 2, find (i) the greatest height reached by the stone above the ground. (ii) the velocity with which it strikes the ground (iii) time taken to reach the maximum height

Using the information given in example 2, find (i) the greatest height

1.	Using the information given in example 2, find (i) the greatest height reached by the stone above the ground. (ii) the velocity with which it strikes the ground (iii) time taken to reach the maximum height
Answer» Solution :Let.s be the HEIGHT covered in upward motion then `v^(2)=u^(2)+2gs` `0=(14.7)^(2)+2xx(-0.8)s` `rArr s=((14.7)^(2))/(19.6)=11.025m` `therefore` The greatest height above the ground =s+s =11.025+196 =207.025m (ii) For the DOWNWARD motion of the stone, u=0,g=`9.8m//s^(2)`, s=207,028m USING `v^(2)=u^(2)+2gs` `=0+2xx(9.8)xx207.025` `rArr v=63.7m//s` (iii) Let t be the TIME taken to REACH the maximum height. Then, for the upward motion `u=14.7m//s, v=0g=-9.8m//s^(2)` Using v=u+gt, we get `t=(v-u)/(g)=(0-14.7)/(-9.8)=1.5s`