Finding the magnitude of force given acceleration?

[disque]

A 2.4 kg toy locomotive is pulling a 1.3 kg caboose. The frictional force of the track on the caboose is 0.46 N backward along the track. If the train is accelerating forward at 3.1 m/s2, what is the magnitude of the force exerted by the locomotive on the caboose




Tried doing 3.7(3.1)+.46=11.93
which equals 12 after sig figs, but it is wrong and I am very confused

Please help, thanks a lot

 

[LowlyPion]

Welcome to PF.

The force on the caboose from the locomotive won't involve the mass of the locomotive.

If the caboose is being accelerated then f = 1.3*a + .46 should be the way to find it.

 

[disque]

Alright thanks a lot
Appreciate it