Force is the product of mass and acceleration .
The question is ask to find acceleration.
But acceleration is the ratio of the force and the mass.
where 600kg is the mass and 7kN is the force
NB: kilo is 1000
now we have to multiply 7N by 1000
by doing so you will have 7000N
which is the force.
Now to find the acceleration: force/ mass
which is 7000/600
therefore the maximum acceleration is 11.667
"with the wind" is a tail-wind, and the speeds are added to get the groundspeed.
"against the wind" is a head-wind, and the windspeed is subtracted from the airspeed.
Then the tangent of angle-Θ is (Ay / Ax).