If i have a small toy boat with a sail, and i attach a fan onto it, FACING THE S

Question

If i have a small toy boat with a sail, and i attach a fan onto it, FACING THE SAIL, which runs by solar. Once the fan turns on will the boat move or will it remain at rest. Apparently it wont because according to Newtons third law the sail will give an equal force back on to the air pushed by the fan. But that doesnt really make sense, so how do real boats which rely on the wind work? If I turn the fan the other way round, the boat will move as the model is now like a planes engine but why not when the fan is facing the sail??

Explanation / Answer

With a sail and a fan it will not move as you rightly argued from a balance of forces. Even turning the fan around will not lead to much movement, as the fan is pulling on the sail (but to a lesser degree).

In real sail boats you can imagine the fan being on the shore and now the boat can move, as there is no fixed connection between the boat and the fan anymore.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.