Help help help plzzz. A 15-kilogram wagon originally at rest on a level road is pulled by a rope that exerts a constant horizontal force of 45 newton's, If the frictional forces on the wagon total 15 newton's, what will be its acceleration ? * 2.0 〖m/s〗^2
4.0 〖m/s〗^2
15 〖m/s〗^2
30 〖m/s〗^2
3.0 〖m/s〗^2

If a small-diameter open glass tube is partially immersed in a vessel containing mercury, the surface of the mercury inside the tube will be a. lower than the mercury in the vessel, and shaped like the inside of a bowl. b. higher than the mercury in the vessel, and shaped like the inside of a bowl. c. lower than the mercury in the vessel, and shaped like the outside of an umbrella. d. higher than the mercury in the vessel, and shaped like the outside of an umbrella.