An anchor weighing 105 lb in water is attached to a chain weighing 3 lb/ft in water. Find the work done to haul the anchor and chain to the surface of the water from a depth of 35 ft.

The weight of the anchor is 105 lb

The chain weights  3 lb/ft

The length of the chain to be hauled up  be y

Therefore the total work done is 5336 ft-lbs

Explanation:

The weight of the anchor is 105 lb

The chain weights  3 lb/ft

The length of the chain to be hauled up  be y

So the combined weight is

==> (3)(35-y)+100=(205-3y)

Consider a small section of chain of length Δy

The work done by a small section is (205-3y)(Δy)

Total work done to haul up the anchor and the chain can be calculated as

W=∫₀³⁵(205-3y)Δy

  =(175y-3y²/2)²⁵

  =(205(35)-3(35²-0)/2)

  =5336

Therefore the total work done is 5336 ft-lbs

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.