it cant
a sail boat can go twice the speed of the wind in optimal conditions. speedboat 30-40
It depends on the speed of the vessel, the wind speed, the place and how choppy it is.
4x wind speed is so far the best alleged possible.
A sailing boat can not sail directly upwind, sail at about 45 degrees to the wind and tack (turn the boat through the wind) to the other side of the wind and continue in this zig-zag manner up wind.
A boat can sail into the wind by sailing backwards and forwards (tacking) at an angle to the wind and so making her way up.
Wind!
To sail against the wind, a boat has to 'tack'. This means that instead of sailing straight into the wind (which would get you nowhere) you sail in a zig-zag in the direction you intend to go. On each tack, the wind is on a different side of the sail.
A sail is a piece of fabric attached to a boat, causing the wind to drive the boat along.
This will depend on a couple different things: ~boat ~wind pressure ~type of sails they can all change how fast the boat is going and in which direction
the force is there and it is easier to row
a boat a sail and the wind
Because there is more surface area for the wind to push against, so therefore increasing the speed of the boat.