Kinematics Question 208
Question: A body falling for 2 seconds covers a distance $ S $ equal to that covered in next second. Taking $ g=10m/s^{2},S= $ [EAMCET (Engg.) 1995]
Options:
A) 30 m
B) 10 m
C) 60 m
D) 20 m
Show Answer
Answer:
Correct Answer: A
Solution:
If u it’s the initial velocity then distance covered by it in 2 sec $ S=ut+\frac{1}{2}at^{2}=u\times 2+\frac{1}{2}\times 10\times 4=2u+20 $ -(i)
Now distance covered by it in 3rd sec $ {S _{3^{rd}}}=u+\frac{g}{2}( 2\times 3-1 )10=u+25 $ -(ii)
From(i) and (ii), $ 2u+20=u+25\Rightarrow u=5 $
$ \therefore $ $ S=2\times 5+20=30\ m $
