A wedge Y with mass of 10 kg and all frictionless surfaces and the inclined surface making 37∘ with horizontal. A block X with mass 2 kg is placed at the highest point of the wedge as shown in figure is at rest. At t=0 wedge (Y) is pulled toward right with constant force (f) of 24 N. Taking the block X at rest at t=0, the time taken by it to slide down 8.8 m on the slope, while Y is on the move, is ______ s. (take tan(37∘)=3/4 and g=10 m/s2)
(A)2✓ Correct
(B)4
(C)2
(D)22
Answer: (A)
Solution
On the frictionless surfaces the horizontal pull is shared by the wedge and the block, so to the standard approximation the wedge accelerates as aw=M+mf=10+224=2m/s2 towards the right. Working in the (non-inertial) frame of the wedge, the block on the 37∘ face feels gravity pulling it down the slope and the pseudo-force pushing it up the slope, so its acceleration along the slope is arel=gsin37∘−awcos37∘=10×53−2×54=6−1.6=4.4m/s2. Starting from rest, the distance along the slope is s=21arelt2, so 8.8=21×4.4×t2 gives t2=4. The block takes 2 s to slide 8.8 m down the slope.
JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Single correct option