Wednesday

July 30, 2014

July 30, 2014

Posted by **Minte** on Thursday, December 27, 2012 at 10:48pm.

- physics -
**drwls**, Thursday, December 27, 2012 at 11:36pmWith no river flow, the boat crosses the river at 90/4 = 22.5 meters/min.

With river flow, it's speed relative to water is the same as above, but it crosses at a speed of 90/5 = 18 m/min, relative to and perpendicular to the shore.

Consider the vector right triangle with sides of river speed, speed relative to shore, and speed relative to water.

If v is the river speed,

v^2 + 18^2 = 22.5^2

Solve for v.

**Related Questions**

physics - A boat heads directly across a river 39 m wide at 3.9 m/s. The current...

physics - your boat departs from the bank of a river that has a swift current ...

science - A boat crossing a .2 mile wide river is heading perpendicularly ...

Precalc - A boat that travels at 16 knots in calm water is sailing across a ...

math - a boat crosses a river and arrives at a point on the opposite bank ...

Calculus - A boat crosses a river and arrives at a point on the opposite bank ...

CALC urgent please - A boat crosses a river and arrives at a point on the ...

physics - A child in danger of drowning in a river is being carried downstream ...

Algebra 2 - The excursion boat on the river takes 2½ hours to make the trip to a...

physics 11 - A river has a current of 5 m/s. A boat tries to head directly ...