Highly selective Backlog Qs for JEE MainPhysicsWork, Power and Energy
With what minimum speed v must a small ball should be pushed inside a smooth vertical tube from a height h , so that it may reach the top of the tube? Radius of the tube is R . (Assume radius of cross-section of tube is negligible in comparison to R .)
Options
- A2 g(h+2 R)
- B5 2 R
- Cg(5 R-2 h)
- D2 g(2 R-h)
Correct answer
D. 2 g(2 R-h)
Step-by-step solution
For minimum v , velocity of ball at the topmost point will be zero. Byconservationof energy, 1 2 m v^2=m g(2 R-h)v= 2 g(2 R-h)