How do I find force given mass and constant velocity

[Solid]

Homework Statement

A farm tractor tows a 3900kg trailer up a 16degree incline with a steady speed of 3.0 m/s. What force does the tractor exert on the trailer? (Ignore friction)

Homework Equations

F=ma
W=mg

The Attempt at a Solution

I haven't the slightest clue on where to start

 

[berkeman]

Homework Statement

A farm tractor tows a 3900kg trailer up a 16degree incline with a steady speed of 3.0 m/s. What force does the tractor exert on the trailer? (Ignore friction)

Homework Equations

F=ma
W=mg

The Attempt at a Solution

I haven't the slightest clue on where to start

Since the speed is constant, acceleration is zero, so F=ma gives you zero force for any acceleration.

Instead, use energy considerations. What it the change in gravitational potential energy (PE) per time for that tractor with that weight moving upward? And what is the equation that relates Power, Energy and Time?

 

[Solid]

Oh, we're not that far into it. We haven't studied energy yet. This question doesn't take into account Normal force either. We have many formulas relating displacement, time, acceleration, and velocity, but I don't think any of them come into play.

We also have Fx = Fxcosx Fy= Fycosy; x and y are theta

 

[iRaid]

\SigmaF = -Ff + Fg = ma (0 since it's constant velocity)
mu_kF_N + mg = 0

There's what you get from the FBD.