What is the net force of a car in a picture below

What is the coefficient of kinetic friction μk between the block and the tabletop?

What are the necessary conditions for fusion?

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)