Search for question
Question

The rectangular cistern (storage tank for rainwater) shown has its

top 15 ft below ground level. The cistern, currently full, is to be

emptied for inspection by pumping its contents to ground level.

Assume that the water weighs 62.3 lb/ft³.

Complete parts (a) through (d) below.

How much work does it take to empty the tank?

(Round to the nearest integer as needed.)

ol

15

25

y

11 ft

b. How long will it take a-hp pump, rated at 375 ft-lb/sec to pump the tank dry?

Ground level

10 ft

20 ft

minutes (Round to the nearest integer as needed.)

c. How long will it take the pump in part (b) to empty the tank halfway? (It will be less than half the time required to empty the tank completely.)

minutes (Round to the nearest integer as needed.)

d. What are the answers to parts (a) through (c) in a location where water weighs 62.13 lb/ft³? Recall the pump is rated at 375 ft-lb/sec.

In a location where water weighs 62.13 lb/ft³, it would take

(Round to the nearest integer as needed.)

What are the answers to parts (a) through (c) in a location where water weighs 62.58 lb/ft³? lb/ft³? Recall the pump is rated at 375 ft-lb/sec.

of work to empty the tank. The pump can pump the tank dry in

In a location where water weighs 62.58 lb/ft³, it would take

(Round to the nearest integer as needed.)

of work to empty the tank. The pump can pump the tank dry in | minutes. It will take the pump minutes to empty the tank halfway.

minutes. It will take the pump minutes to empty the tank halfway.

Fig: 1