Math 150B/155A Worksheet for 6.4
  1. A spring, whose unstretched length is 1 meter, stretches to a length of 3 meters when a force of 3 newtons is applied. Find the work needed to stretch the spring to a length of 2 meters from its natural length.
  2. How much work is required to stretch the spring in Problem 1 to a length of 4 meters?
  3. A spring, whose unstretched length is 2 meters, is compressed to a length of 1/2 meter when a force of 10 newtons is applied. Find the work required to compress the spring to a length of 1 meter.
  4. How much work is required to compress the spring in Problem 3 to a length of 1.5 meters?
  5. A spring, whose unstretched length is 4 feet, stretches to a length of 8 feet when a force of 2 pounds is applied. If 9 foot-pounds of work is expended to stretch this spring from an unstretched position, what is its total length?
  6. If 8 foot-pounds of work is expended on the spring in Problem 5, how far is it stretched?
  7. How much work is required to pump all the water over the top of a full cylindrical tank that is 4 meters in diameter and 6 meters high?
  8. How much work is required to pump half the water over the top of the tank in Problem 7?
  9. A full tank in the shape of an inverted right circular cone is 8 meters across the top and 4 meters high. How much work is required to pump all the water over the top of the tank?
  10. If the surface of the water in the tank of Problem 9 is 2 meters below the top of the tank, how much work is required to pump all the water over the top of the tank?
  11. A water tank in the shape of a hemispherical bowl of radius 4 meters is filled with water to a depth of 2 meters. How much work is required to pump all the water over the top of the tank?
  12. If the water tank in Problem 11 is completely filled with water, how much work is required to pump all the water to a height 2 meters above the tank?
  13. A swimming pool is in the shape of a rectangular parallelepiped 6 feet deep, 30 feet long, and 20 feet wide. It is filled with water to a depth of 5 feet. How much work is required to pump all the water over the top?