A body falling from rest was obsconds. How long (in seconds ) had it been falling befor it was boserved.

A body falling from rest was obsconds. How long (in seconds ) had it b

1.	A body falling from rest was obsconds. How long (in seconds ) had it been falling befor it was boserved.
Answer» Solution :Let the body be FALLING for (t) second and DISTANCE TRAVELLED by (S) metres before the observations arte taken. Distance travelled in (t+2)seconds ` = (S + 78.4) m . Then ` S = 1/2 xx 9. 8 xx t^2` …(i)` ltvrgt and ` (S+ 7.8 ) = 1/2 xx (9.8) ( t+2)^2` ...(II) Solivng (i) and (ii) , we get ` t= 3 s`.