Homework Help: Pre calculus, vectors

Posted by Halala on Tuesday, February 26, 2013 at 7:04am.

A straight river flows at a speed of 20km/h. A boater starts at the south shore and heads in ths direction of 70degrees from the shore. The boat has a speed of 20km/h in still water. Find the true speed and direction of the boat.

Pre calculus, vectors - Henry, Wednesday, February 27, 2013 at 9:09pm
Vb = 20km @ 70o + 20km @ 0o.

Vb = X + Yi.
Vb = (20*cos70*20) + (20*sin70)i
Vb = 26.84 + 18.79i

tanA = Y/X = 18.79/26.84 = 0.70022
A = 35o = Direction.

Vb = X/cosA = 26.84/cos35 = 32.8 km/h =
Velocity of the boat.

Answer this Question

Related Questions

Physics - A river is flowing 4.0 m/s to the east. A boater on the south shore ...
Physics - A river is flowing 4.0 m/s to the east. A boater on the south shore ...
Math: Calculus - Vectors - A boat travels at a speed of 5 m/s in still water. ...
Vectors - I hope that the diagram I have drawn for myself matches the one in ...
Physics - A river flows due east at 1.42 m/s. A boat crosses the river from the ...
Physics - A river flows due East at 0.979 m/s. A boat crosses the river from the...
physics - A river flows due east at 1.50 m/s. A boat crosses the river from the ...
physic - Hi!Question: A river flows due east at 1.70m/s.A boat crosses the river...
physics - A river flows due east at 1.34 m/s. A boat crosses the river from the ...
physics - A river flows due east at 2.00 m/s. A boat crosses the river from the ...

For Further Reading

First Name:
School Subject:
Answer: