atiyya

a duck is swimming across a river.The duck can swim at maximum speed of 2m\s in still water. If the duck is swimming as hard as possible straight across a river that is running at 4m\s, what is the duck's overall speed, relative to the goose sitting on th...

A boat is heading directly North acroos a river at 5km\h. The river is flowing east at 3km\h. a) what is the actual velocity of the boat? b) how far down stream does it land if the trip takes 0.5 hrs. c) how wide is the river?

A boy has a mass 40kg and a girl of mass 30kg play on a see-saw, where must the girl sit to make it balance?