Solve Weight & Free Fall on a Far-Away Planet - Astronaut Problem

[youxcrushxme]

Hey guys, I'm confused about this problem -

On a planet far, far away, an astronaut picks up a rock. The rock has a mass of 5.80 kg, and on this particular planet its weight is 40.0 N. If the astronaut exerts an upward force of 43.3 N on the rock, what is its acceleration?

I thought you just did a=1/m*Fnet. The mass is 5.8, and I thought Fnet would be 43.3n+40N but my answer is not coming out right. If anyone could help me out I'd really appreciate it!

 

[neutrino]

What about the direction of the forces? Fnet is a vector sum.

 

[youxcrushxme]

I wasn't sure about that, I thought maybe -40N because that's it's weight and then the +43.3N because it's being thrown upward but it keeps saying my answer is wrong.

 

[neutrino]

You're right. It should be 3.3/5.8 ms^-2 (assuming the data is right). May be you didn't provide the answer to the required number of decimal places.

 

[youxcrushxme]

I got it, I think I may have forgotten to make the 40N negative or something...thanks so much!