Adancer lifts a 200-kg barbell with an acceleration of 3 m/s2. how much force does the weightlifter use to raise the barbell

Describe uniform velocity and variable velocity in short

It is really hard for me right know

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?