1. A weight lifter lifts 100 kg of mass from the floor to a position above her head, 2.2 meters off the floor. a. How much work did she do on the mass?

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

conservation of mass

mass before something happens = mass afterwards