A spring scale A and a lever scale B having equal lever arms are
fastened to the roof of an elevator, and identical packages are
attached to the scales as shown. Knowing that when the elevator
moves downward with an acceleration of 1 m/s² the spring scale
indicates a load of 60 N, determine (a) the weight of the packages,
(b) the load indicated by the spring scale and the mass needed to
balance the lever scale when the elevator moves upward with an
acceleration of 1 m/s².
Fig: 1