Performance Boat Shop

how do you calculate a boats speed?

I have done an experiment which involved a boat with a mass of 25.2g traversing down a trough of water but when i increase the mass by 7.5g the speed doubles? why does this happen? (i have repeated this many times) thanks The only variable in this is the mass, a weight is used to pull the boat along the water and im always using the same weight etc..

Public Comments

1. It could be pulled by a person, that when he or she sees you adding 7.5g more, pulls it so that it goes twice as hard. Do you see that there is not enough info?
2. Ek=1/2mV^2, it may help.