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← JEE Main 2022 · 27 Jul · Shift 2
PhysicsInteger+4 / -1Question 60 of 90

JEE Main 2022 · 27 Jul · Shift 2, Physics question 60

Two inclined planes are placed as shown in figure. A block is projected from the Point A of inclined plane AB along its surface with a velocity just sufficient to carry it to the top Point B at a height 10 m. After reaching the Point B the block slides down on inclined plane BC. Time it takes to reach to the point C from point A is t(2+1)t\left(\sqrt2+1\right) s. The value of t is ______.

(use g = 10 m/s2^2)

Two smooth inclines meeting at B, 10 m high: AB at 45° on the left and BC at 30° on the right.
Answer and worked solution

Official answer: 2

Up AB (10210\sqrt2 m, deceleration 525\sqrt2): reverse of starting from rest, t1=2⋅10252=2t_1=\sqrt{\frac{2\cdot10\sqrt2}{5\sqrt2}}=2 s.

Down BC (20 m, acceleration 5): t2=8=22t_2=\sqrt8=2\sqrt2 s.

Total 2(2+1)2(\sqrt2+1) s.

Answer: 2