Can someone check my work for this problem? Newton's second law of motion

Question

At $560$ metric tons, the airbus A-$380$ is the world's largest airliner. Whats the upward force on an A-$380$ when the plane is flying (a) at a constant altitude and (b) accelerating upward at $1.1 \: m/s^2$

So I know $f=ma$

So for part a I did

$f= 560 * 10^3$ kg ($9.8 \: m/s^2$)

$f=5,488,000 N$

So for part b I did

$f=560 * 10^3$ kg ($1.1 \: m/s^2$)

$f=616,000 N$

Are these answers correct?

Answer 1

Think about it for a moment.

You say that the force when the airplane is flying at a constant altitude is $5,488,000$ newtons, but when the airplane is accelerating upwards, the force is $616,000$ newtons.

That means that if I am pushing the plane upward so it is flying at a constant altitude, then decrease the upward force bt $4,872,000$ newtons, the airplane will suddenly start moving upward?

Answer 2

If you consider the numbers you got, you should be able to tell you have made a mistake somewhere - surely to accelerate upwards it takes more force. Your error lies in the fact that you used only an acceleration of $1.1\text{m/s}^2$ for part b, you forgot to consider gravity.

Answer 3

You answer for part a is right.

For the second you are wrong since it is accelerating at 1.1 units. The other force acting on it is gravity which is opposite so it has to oppose this and is then also accelerating at 1.1 units so the net force is m*(9.8+1.1) units where m is mass.

So the answer is 6,104,000