Question #6fc66

1 Answer
P dilip_k
Aug 26, 2016

One cyclist traveling towards North-West and another towards South.So angle between them is #theta=(45+90)^@=135^@#

Let the starting point of journey of two cyclists be O. After t hr first cyclist reaches at A traveling @ 22km/hr and at the same time the second cyclist reaches at B traveling @ 14km/hr .

#"So in "DeltaAOB#

#/_ AOB=theta=135^@ #

#OA=22t" km"#

#OB=14t" km"#

#AB=80" km"#

Applying triangle law

#AB^2=OA^2+OB^2-2OA*OBcostheta#

#=>80^2=(22t)^2+(14t)^2-2*22t*14tcos135^@#

#=>t^2(484+196+616*cos45^@)=6400#

#=>t^2(484+196+616*1/sqrt2)=6400#

#=>1115.58t^2=6400#

#=>t^2=6400/1115.58#

#=>t=sqrt(6400/1115.58)~~2.39hr#

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