1. A variable force of 4√ newtons moves a particle along a straight path wien it is a meters from the origin. Calculate the work done in moving the particle from z=4 to z = 16.
2. A spring has a natural length of 40 cm. If a 60-N force is required to keep the spring compressed 10 cm, how much work is done during this compression? How much work is required to compress the spring to 1 a length of 25 cm?
3. A circular swimming pool has a diameter of 24 ft, the sides are 5 ft high, and the depth of the water is 4 ft. How much work is required to pump all of the water out over the side? (Use the fact that water weighs 62.5 lb/ft³.