ExamBro
ExamBro
JEE Mains · Physics · STD 11 - Newtons laws of motion
  • JEE Mains 2021
  • Hard
  • MCQ

The boxes of masses \(2\, {kg}\) and \(8\, {kg}\) are connected by a massless string passing over smooth pulleys. Calculate the time taken by box of mass \(8\; {kg}\) to strike the ground starting from rest. (use \(\left.{g}=10\, {m} / {s}^{2}\right)\) (in \({s}\))

Pick an option to check your answer.
Verified Solution

Answer & Solution

Correct Answer

(D) \(0.4\)

Step-by-step Solution

Detailed explanation

\(\left({m}_{1} {g}-2 {T}\right)={m}_{1} {a}.....(1)\)

\({T}-{m}_{2} {g}={m}_{2}(2 {a})\)

\(2 {T}-2 {m}_{2} {g}=4 {m}_{2} {a}.....(2)\)

\({m}_{1} {g}-2 {m}_{2} {g}=\left({m}_{1}+4 {m}_{2}\right) {a}\)

\({S}=\frac{1}{2} {at}^{2}\)

\(\frac{0.2 \times 2 \times 4}{10}={t}^{2}\)

\({t}=0.4\, {sec}\)

Same subject
Explore more questions on app
From JEE Mains
Explore more questions on app