Magnitude of resistive force

[PhunWithPhysics]

Tell me if im wrong or not, but you have a boat that weighs 1.70x10^8 kg and the engines are moving it with a forse of 7.40x10^5 Newtons.
a.) I think that the magnitude of the resistive force exerted by the water is equal to the force the boat witch is 7.40x10^5, is this correct?
b.) how do I find the upward buoyant force exerted on the boat?
Any help would be great

[bloccubed]

yes a is correct

part b is a (mg) problem now just solve for m times g

[hotvette]

I'm not sure you have enough information for the first part. I believe what you said is true only if the boat is travelling at a constant speed (ie. a = 0).