Two balls are dropped to the ground from different heights . One ball is dropped `2.0`s after the other , but both strike the ground at same time `5.0`s after the 1 st is dropped . (a) What is the diference in the heights from which they were dropped ?(b) From what height was the first ball dropped ?

Explanation

(a) For the first ball `s=h_(1),v=0,t=5 sec `
`s=ut+1/2at^(2), h_(1)=0xx5+1/29.8xx5^(2)=122.5m`
For the second ball `s=h_(2),u=0, t=3sec :. H_(2)=1/2gt^(2)=1/2xx9.8xx9=4.9xx9=44.1m`
Difference in heights `h=h_(2)-h_(1)=122.5-44.1=78.4m`
The first ball was dropped from a height of `h_(1)=122.5m`.