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QJEEM21Ph66d8: JEE Main 2021 Physics - Class 11 JEEM21Ph66d8 Solution: A block of mass m slides on the wooden wedge, which in turn…

A block of mass m slides on the wooden wedge, which in turn slides backward on the horizontal surface. The acceleration of the block with respect to the wedge is : Given m = 8 kg, M = 16 kg Assume all the surfaces shown in the figure to be frictionless.

JEE Main 2021 (Online) 1st September Evening Shift Physics - Laws of Motion Question 68 English

Multiple Choice Options

  • A 43g{4 \over 3}g
  • B 65g{6 \over 5}g
  • C 35g{3 \over 5}g
  • D 23g{2 \over 3}g

Step-by-Step Verified Solution

Let acceleration of wedge is aw and acceleration of block w.r.t. wedge is ab

For the wedge w.r.t. ground

JEE Main 2021 (Online) 1st September Evening Shift Physics - Laws of Motion Question 68 English Explanation 1
N cos60 ∘^\circ = Maw = 16aw

⇒\Rightarrow N = 32aw

F.B.D. of block w.r.t. wedge

JEE Main 2021 (Online) 1st September Evening Shift Physics - Laws of Motion Question 68 English Explanation 2
Balancing vertical forces

N = 8g cos30 ∘^\circ −- 8aw sin30 ∘^\circ ⇒\Rightarrow 32aw = 4 3\sqrt 3 g −- 4aw

⇒\Rightarrow aw = 39{{\sqrt 3 } \over 9} g

Along incline plane

8g sin30 ∘^\circ + 8aw cos30 ∘^\circ = mab = 8ab

ab = g ×\times 12+39{1 \over 2} + {{\sqrt 3 } \over 9} g . 32=2g3{{\sqrt 3 } \over 2} = {{2g} \over 3}

Option (d)

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