At what rate does the mass accelerate?

[cchabound27]

Can someone help explain this question to me, i know the answer to be 5 m/s^2 but thought it was 10 m/s^2. An anstronaut on the moon applies a 100 N horizontal force to a 10 kg mass at rest on a table. At what rate does the mass accelerate?

 

[Matterwave]

The answer is 10m/s^2 assuming no friction. Perhaps there's some friction? Otherwise, by straightforward application of F=ma gives a=F/m=100N/10kg=10m/s^2