Upward force and tension when helicopter lifts truck

[saber1357]

Homework Statement

A 15,000 kg helicopter lifts a 4500 kg truck with an upward acceleration of 1.4 m/s2.
Calculate (a) the net upward force on the helicopter blades from the air and (b) the tension in
the cable between helicopter and truck.

Homework Equations

T = mg

The Attempt at a Solution

I was able to calculate the upward force, but I am having difficulty finding out how to calculate the tension. I know that the truck is pulling the heli with the force of gravity, and the helicopter is pulling the truck with the upward force. But how do I relate the two?

 

[Hootenanny]

Hint: If the truck was sat on the [frictionless] ground, how much force would be required to accelerate it at 1.4m.s^-2? What is the weight of the truck? How do you sum forces?