<p>A boat that can move at 5 km/hr in still water is crossing a river whose current is 2 km/hr. The problem is to steer the boat so that it will land directly across the river from where it started. The solution to the problem is best represented by which of the following?</p>
<p>The answers are pictures, I cant really draw them here.
Can someone please explain this one?</p>
<p>Also, could someone please explain the right hand rule to me?</p>
<p>I think you need to choose which of the drawings of the question , it must be a drawing where he crosses the river in a certain way to get to the same point at the other bank in spite of the river current which is to the right or left... and still
Pythagoras is applicable.. </p>
<p>The current is perpendicular to the displacement vector. So if you try to go from I to F without steering you will begin to move in a circular motion. So you have to steer the boat in such way that you can go forward. To do this you have to steer the boat with approximately 24º (from the displacement vector) this way the velocity will have a component (Lets call it the x component) that is 2 m/s and has the opposite direction of the current. This way you will move directly forward.To find this angle just imagine a triangle were the hypotenuse is 5 and one of the legs is 2.</p>
<p>I think this is the correct answer. Just hope I was clear enough.</p>
<p>right hand rule: this is a (literal) rule of thumb that allows you to get the signs right when working with current flow and magnetic fields. If you point your right thumb in the positive direction of current flow then curl your fingers on that hand, they will point in the positive direction of the magnetic field. Conversely, if you curl the fingers of your right hand in the direction of positive magnetic field then extend your right thumb, it will point in the direction of positive current flow.</p>
<p>It is also used to distinguish a right-threaded screw, which advances along the direction of the right thumb when twisted in the direction that the fingers curl, from a left-threaded screw, which does the opposite.</p>
