a 75 hp merc goes 19 mph
8-15
50 mph
Depends on how it is geared.
70
There is no direct correlation between horse power and speed. That is to say you can't put an exact number because of all the other variables. I have seen a car with about 75 hp do well over 150 mph and my farm tractor with 72 hp only has a top speed of 30 mph. There is an old saying "how fast something will go depends on how much money you want to spend".
75 hp
1 hp = 745.7 watts, so 75 hp = 55.93 kilowatts
A 3HP motor can reach speeds up to at least 30 mph depending on what you are using it for.
4-5 mph depending on wind, tides etc..
About 10 to 12 on plane
135kg