Sailboat Moving Forward

In the picture

1. 1The sail
2. 2The wind arrow
3. 3The underwater fin
4. 4The forward arrow at the bow

Examples

• A sailing dinghy with a centerboard
• A kite pulling sideways while your feet grip the ground

Quiz: Sailboat Moving Forward (Age 12)

1. 1

   Why does pushing the sail from the side make a sailboat move forward instead of only sideways?

   • The wind pushes the sail only backward, so the boat moves away from the wind.
   • The underwater fin pushes back on the water, which turns the sideways push into forward motion.
   • The sail removes the sideways force, so the boat drifts forward on its own.
2. 2

   What is the main job of the underwater fin below the boat?

   • It catches wind under the water to pull the boat.
   • It makes the boat heavier so it cannot move sideways.
   • It pushes against the water, helping stop the boat from sliding sideways.
3. 3

   How do the wind and water forces work together on a sailboat?

   • Wind pushes the sail sideways, water pushes back on the fin, and the two forces combine into forward motion.
   • Wind pushes the boat forward, while water pushes the sail sideways.
   • Water pushes the sail, while wind pushes the fin forward.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.