# when going east at 10 kmph a train moving with const. velocity appears to be moving exactly north east . when my velocity is increased to 30 kmph east it appears to be moving north.a.what is the velocity of train in noth?b.what is the velocity of train along east?​c.what speed should i move north so that train appears to move exactly south-eadt?please provide commplete  solution in details.. :)

Arun Kumar IIT Delhi
10 years ago
Hello
You should apply concept of reletive velocity here
$\\\vec v_{man}=10\vec i \\\vec v_{train}=x\vec i +y \vec j \\\vec v_{train,rel}=(x-10)\vec i +y \vec j \\=>x-10=y since both component should be equal \\ to be in in north east \\\vec v_{train,rel}=(x-30)\vec i +y \vec j \\=>x-30=0 \\=>x=30 =>y=20 \\\vec v_{train}=30\vec i +20 \vec j$
Now you can find everything.
Thanks & Regards
Arun Kumar
Btech IIT Delhi
shalini
14 Points
10 years ago
Thanq very much Sir :)
but why should x-10 be equal to y??? :/
shalini
14 Points
10 years ago
Ok ok..is it because angle is 45 degree so...x- component and y- component must b equal????.. Am I right Sir???