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A car is moving on a horizontal curved road with radius 50 m. The approximate maximum speed of car will be, if friction between tyres and road is 0.34. [take g=10 m s⁻²]

Asked in JEE Main 29th Jan 1st Shift 2023 · Banked roads and the conical pendulum

Answer: (2) 13 m s⁻¹

Step-by-step solution

Idea: on a flat bend, friction alone supplies the centripetal force, so vₘₐₓ=√μ g r.

(mv²)/r≤μ mg gives, after the mass cancels,

vₘₐₓ=√μ gr=√0.34×10×50=√170

vₘₐₓ≈13 m s⁻¹.

About 47 km/h — modest, which is exactly why real bends are banked rather than left flat.

Why the other options are wrong

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