Highly selective Backlog Qs for JEE MainPhysicsMotion in Two Dimensions
Four persons K , L , M , N are initially at the four corners of a square of side d . Each person now moves with a uniform speed v in such a way that K always moves directly towards L , L directly towards M , M directly towards N , and N directly towards K . The four persons will meet at a time
Options
- Ad v
- Bd 2 v
- C2 d v
- DThe four persons will never meet
Correct answer
A. d v
Step-by-step solution
The velocity of K throughout the motion towards the centre of the square is v cos 45 ° and the displacement covered by this velocity will be KO . ∴ t = K O v cos 45 ° = ( 2 d 2 ) v 2 = d v