Suppose that 2j of work is needed to stretch a spring from its natural length of 30cm to a length of 42cm
how much work is needed to stretch the spring from 35 to 40cm

so hookies law
work = kx^(2)

i get

k = 2/144

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano. the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? a.positive force, balanced force, negative force b.negative force, balanced force, positive force c.positive force, unbalanced force, negative force d. negative force, unbalanced force, positive force