> How do you go 155 mph unless the wind is blowing 155 mph? <
The wind is a force. When the wind is to your back, it will add to your speed. You will go faster and faster and faster until the wind force is balanced out by other forces. The balancing forces here are road friction and air resistance.
Maybe this will help. Think of the land yacht’s speed as money in the bank. You have nothing in the bank now. You decide to add $10 per day. You have $10 then $20, then $30 etc. That $10 deposit is not a limit. It just adds to what you already have.
Then you sign up for an automatic payment plan that costs $10 per day. Your deposit is now balanced out by a withdrawal. Your savings will no longer increase.
not exactly. It’s a complex trigonometry and you need to read a sailing book.
If the wind is 25mph and you are traveling at 25 mph (in the same direction) you feel no wind, so no force.
That is why people in a hot air balloon feel no wind- they are moving WITH the wind.