Two forces 3n and 4n act on a 20kg mass. calculate the magnitude of their resultant force if the angle between the two forces is 60°

Atomic nuclei of almost all elements consist of

Use the profile illustrated for problem (1). assume that the layer of silty sand fill (sm) is placed over the entire site. estimate the thickness of the fill (h - in feet) that will cause the effective vertical stress at the center of the clay layer to increase by 517.5 pounds per square foot.

Am i correct on these two physics questions?