Inside an ice rink, Mary (40 kg), standing on the ice, accidently pushes on the wall at the right side with a force of 85 N and starts to move away to the left. Assume the friction between her shoes and the ice is 5.0 N.

1. Draw a force diagram for all the forces acting on Mary at this instant.
2. Find the magnitude and direction of the net force received by her.
3. Find the magnitude and direction of her pushing-off acceleration.
4. If starting from rest, what is her skating velocity when her hand loses contact with the wall at the end of 0.5 seconds?