NTA Abhyas JEE Main2020PhysicsRotational MotionPractice
A disc of radius R rolls without slipping at a speed v along the positive x -axis. The velocity of a point P at the instant shown in the figure is
Options
- Av → P = v + v r sin θ R i ^ + v r cos θ R j ^
- Bv → P = v + v r sin θ R i ^ - v r cos θ R j ^
- Cv → P = v r sin θ R i ^ + v r cos θ R j ^
- Dv → P = v r sin θ R i ^ - v r cos θ R j ^
Correct answer
B. v → P = v + v r sin θ R i ^ - v r cos θ R j ^
Step-by-step solution
We have ω = v R for pure rolling. The velocity of point P is resultant of two velocity vectors shown as arrows in the figure. Hence, v → P = v x i ^ + v y j ^ or v → P = v + v r sin θ R i ^ - v r cos θ R j ^