Question

Question 9.

9. A stick of length 10 units rests against the floor and a wall of a room.
If the stick begins to slide on the floor then the locus of its middle points -
(A) x2 + y2 = 2.5
(B) x2 + y2 = 25
(C) x2+ y2 = 100
(D) none

Answer 1

Correct option is the answer B

Answer 2

Answer:

B) x^2 + y^2 = 25

Step-by-step explanation:

let midpoint of rod be ( h , k )

let the point where the stick touches the wall and floor be A and B respectively

using section formula , we get A = ( 0 , 2k ) and B = ( 2h , 0 )

now , using distance formula , we can find AB

AB = $\sqrt( 4k^2 + 4h^2)$ = 10 ( given )

=> $4k^2 + 4h^2 = 100$

=> $k^2 + h^2 = 25$

=> $x^2 + y^2 = 25$

HOPE IT HELPS !!!!