NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
A car moves uniformly along a horizontal sine curve y = a sin ( x / α ) , where a and α are certain constants. The coefficient of friction between the wheels and the road is equal to k . The maximum constant speed at which the car can travel without sliding is
Options
- Aα kg a
- B- α kg a
- Ckg α a
- D- kg α a
Correct answer
A. α kg a
Step-by-step solution
Step I : Determine the radius of curvature of given curve at point P (x, y). ∵ y = a sin x α ∴ d ⁡ y d ⁡ x = a α cos x α ∴ d ⁡ 2 y d ⁡ x 2 = - a α 2 sin x α ∴ the radius of curvature is R ⁡ = 1 + d ⁡ y d ⁡ x 2 3 / 2 d ⁡ 2 y d ⁡ x 2 R ⁡ = 1 + a 2 α 2 cos 2 x a 3 / 2 - a α 2 sin x α ...(i) Step II : Relate the friction and centripetal acceleration. In this case, centripetal acceleration is provided