JEE Main 2026 · 6 Apr · Shift 2 · Physics Q46

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PhysicsInteger+4 / -1Question 46 of 75

A block takes $t$ time to slide down a plane inclined at 45° to the horizontal. If the surface is made smooth (frictionless), the block takes time $\dfrac t2$ to slide down the plane. The coefficient of friction between the block and the inclined plane is $\left(\dfrac\alpha{100}\right)$ . The value of $\alpha$ is ________.

Your answer

Answer and worked solution

Official answer: 75

Times. $t\propto\dfrac1{\sqrt a}$ , so taking twice as long means a quarter of the acceleration.

Acceleration with friction.
$g(\sin45^\circ-\mu\cos45^\circ)=\tfrac14g\sin45^\circ\ \Rightarrow\ \mu=\tfrac34.$

Answer: $\alpha=75$

Topics:Friction Motion in a straight line

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JEE Main 2026 · 6 Apr · Shift 2, Physics question 46