A Force and motion problem

[Darienesque]

Suppose a horse pulls on the rope with a force of 7134.064422651 N at an angle of = 18.955585914° to the direction of motion of a barge, which is headed straight along the positive direction of an x axis. The mass of the barge is 9358.240127247 kg, and the magnitude of its acceleration is 0.155965913 m/s2. What are (a) the magnitude and (b) the direction of the force on the barge from the water?

[Darienesque]

i know you find the force of the barge by multipliying its mass by its accelleration. But i just dont know how it ties in to figureing out the force on the boat from the water?

[Silimay]

You can find the component of the horse's force along the barge using trigonometry, correct? Since you know the net force on the barge = force of horse + force of water, and you know the numerical value of the force on the barge (=barge's mass * acceleration), you should be able to find the force of the water on the barge. It should be slowing or speeding up the barge...check and see. :)