Marisol pushes a 3.0 kg box 7.0 m across the floor with a force of 12 N. She lifts the box to a shelf 1 m above the ground. How much work does Marisol do on the box?
-- Floor portion: Force = 12 N Distance = 7.0 m Work = (12 x 7) = 21 joules
-- Lift portion: Weight of the box = (mass) x (gravity) = (3.0) x (9.8) = 29.4 newtons Force to lift = weight of box = 29.4 N Distance = 1 m Work = (29.4 x 1) = 29.4 joules
