NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
A block is dragged on a smooth horizontal plane with the help of a light rope which moves with a velocity v as shown in figure. The horizontal velocity of the block is
Options
- Av
- Bv sin θ
- Cv sin θ
- Dv cos θ
Correct answer
C. v sin θ
Step-by-step solution
From geometry l 2 = x 2 + y 2 but y is constant, hence differentiating, we have, 2 l d l d t = 2 x d x d t But d l d t = v . Hence horizontal velocity of block, v x = d x d t ⇒ l v = x . v x or v x = l . v x = v sin θ