How far back into the universe are we able to see? Explain

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?

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.)

Which system of units is used by only a small number of countries in the world, including the u.s.