ExamBro
ExamBro
JEE Mains · Physics · STD 11 - Motion in straight line
  • JEE Mains 2021
  • Hard
  • Numerical

A stone is dropped from the top of a building. When it crosses a point \(5\, m\) below the top, another stone starts to fall from a point \(25\, m\) below the top. Both stones reach the bottom of building simultaneously. The height of the building is ..... \(m\).

Pick an option to check your answer.
Verified Solution

Answer & Solution

Correct Answer

(B) \(45\)

Step-by-step Solution

Detailed explanation

displacement of the first stone when second is dropped \(=5 m\),

time difference in dropping of the stones is \(t =\frac{2 h }{ g }=1\; s\)

\(h =\frac{1}{2} g t ^{2}=\frac{1}{2} g ( t -1)^{2}+25 \Rightarrow t =3 \;s\)

thus, \(h =\frac{1}{2} g t ^{2}=\frac{1}{2} \times 10 \times (3)^{2}= 4 5 \;m\)

Same subject
Explore more questions on app