Can anybody answer number 3 please hurry

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?