JEE Main202116 Mar 2021Evening ShiftPhysicsLaws of MotionActual
Statement I: A cyclist is moving on an unbanked road with a speed of 7 km h - 1 and takes a sharp circular turn along a path of the radius of 2 m without reducing the speed. The static friction coefficient is 0 . 2 . The cyclist will not slip and pass the curve g = 9 . 8 m s - 2 Statement II : If the road is banked at an angle of 45 ° , cyclist can cross the curve of 2 m radius with the speed of 18 . 5 km h - 1
Options
- AStatement I is incorrect and statement II is correct
- BStatement I is correct and statement II is incorrect
- CBoth statement I and statement II are false
- DBoth statement I and statement II are true
Correct answer
D. Both statement I and statement II are true
Step-by-step solution
Statement I v max = μ R g = 0 . 2 × 2 × 9 . 8 v max = 1 . 97   m   s - 1 7   km   h - 1 = 1 . 944   m   s - 1 Speed is lower than v max , hence it can take safe turn. Statement II v max = Rg tanθ + μ 1 - μtanθ = 2 × 9 . 8 1 + 0 . 2 1 - 0 . 2 = 5 . 42   m   s - 1 18 . 5   km   h - 1 = 5 . 14   m   s - 1 Speed is lower than v max , hence it can take safe turn.