Question

2 roads OA AND OB MEET AT O FIRM ACUTE ANGLE .A MAN STARTING FROM O TRAVEL 13M ALONG OB and finds his DISTANCE FROM OA IS 12 M HE GOES FURTHER 5 M ALONG OB . FIND HIS DISTANCE FROM OA NOW​

Answer 1

Answer:

Let the dis. b/w two cars after t second be S. Distance covered in t is 20t, so its distance from O will be (800−20t)m

Then the distance covered by second car is 20t m.

2

1

=cos60

o

=

(800−20t)25t

(800−20t)

2

+(25t)

2

−S

2

S

2

=(800−20t)

2

+625t

2

−(40−t)250t

for S to be min, we have

dt

ds

=0

−40(800−20t)+1250t−(40−t)250+250t=0

−42000+2550t=0

t=

51

840

Sr

2

t

=

51

420

[

2

t

]=[8.23]

=8 Sr

Answer 2

Answer:

17m

Step-by-step explanation:

17m is the anser of this question