Apower lifter performs a dead lift, raising a barbell with a mass of 305 kg to a height of 0.42 m above the ground, giving the barbell 1256.66 j of potential energy. the power lifter then releases the barbell, letting it drop towards the ground. determine the magnitude of the vertical velocity of the barbell when it reaches a height of 0.21 m (on the way down) using a mechanical energy approach. then calculate the velocity right as it reaches the ground using a mechanical energy approach. confirm your answer for the velocity of the barbell right before it hits the ground by also calculating this velocity using a projectile motion approach.