JEE Main 2021 — Laws Of Motion Question with Solution
From: JEE Main 2021 (Online) 27th August Evening Shift
Question
The boxes of masse 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 g = 10 m/s2)
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: D
Correct answer
D0.4 s
Step-by-step explanation
(m1g 2T) = m1a (1)
T m2g = m2(2a)
2T 2m2g = 4m2 a (2)
m1g 2m2g = (m1 + 4m2) a
a =
a = m/s2
S = at2
= t2
t = 0.4 sec
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