JEE Mains · Physics · STD 11 - 4.1 newtons laws of motion
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 \({s}\))
- A \(0.34\)
- B \(0.2\)
- C \(0.25\)
- D \(0.4\)
Answer & Solution
Correct Answer
(D) \(0.4\)
Step-by-step Solution
Detailed explanation
\(\left({m}_{1} {g}-2 {T}\right)={m}_{1} {a}.....(1)\) \({T}-{m}_{2} {g}={m}_{2}(2 {a})\) \(2 {T}-2 {m}_{2} {g}=4 {m}_{2} {a}.....(2)\) \({m}_{1} {g}-2 {m}_{2} {g}=\left({m}_{1}+4 {m}_{2}\right) {a}\) \({S}=\frac{1}{2} {at}^{2}\) \(\frac{0.2 \times 2 \times 4}{10}={t}^{2}\)…
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