Engineering Answers

Find the centroid of the solid generated if the region bounded by y = 2- x^2, x=0, and y=0 is revolved about the y-axis.

Find the area between the curves y^2 - y + x = 0 and y^2 = x + 3.

3.9. A hunter desires to go to a point northeast but because of a canyon

he goes ½ mile due east and then turns left and travels ¾ mile in a straight

direction in degrees did he travel in going the ¾ mile?

3-7. A stream has parallel banks and ie 1000 ft across. A boat has traveled

500 it in a straight line making 30° with the bank. At this instant find the distance the boat has gone parallel to the bank and the shortest distance to

the opposite bank.

3-5. A vector is 4 in. long and has a direction-sense of 60°.

(a) Resolve

the vector into horizontal and vertical components,

(b) Find the components

of this vector on lines making 15° and 75° with the horizontal. (c) Find the

components of this vector along and perpendicular to a line making 30° with

the horizontal,

3-3.

Given five vectors whose lengths and direction-senses are as follows:

Ac, is 1.5 in. long and 90°; Aa, is 1.25 in, long and 315°; Aay is 2 in. long and

0°; AQ, is 1.25 in. long and 225°; Ad, is 1.5 in. long and 45°. Find the vector

sum of the first four, and subtract Ad, from this resultant vector.

3-1. A vector Bb is 1 in. long and has a direction-sense of 45°. Vector Cc

is 1½ in. long and has a direction-sense of 150°. Find their vector sum.

put together a document (500 words) in which you evaluate your chosen design solution to the requirements of the customer and the PDS

The city of a population of 161,565 has requested to evaluate its solids waste collection system.

Determine:

i) mean time per collection stop plus the mean time to reach the next stop,

ii) number of pickup locations per load

iii) minimum number of trucks the city must own.

Consider the following data:

a) Average truck capacity =18 m3

b) Average observed compaction ratio =3.28

c) Crew size = 2 persons

d) Number of pickups = 1/week (no rear-of-house service)

e) Average number of residence per stop= 2.5

f) Average uncompact density = 122 kg/m3

g) Average transport time to disposal site including delay and dumping = 1.5 h/trip

h) Average number of trips to disposal site =2/day

i) Rest breaks = 2 at 15 min

j) Average maintenance downtime = 36 min/day

k) Average work day = 8 hours

l) Average percentage of truck out of service for majority repairs = 15%

m) Average number of cans per stop = 2.5/wk at 0.0911 m3/can

A contractor is trying to estimate the distance to be expected of drawdown of 4.81 m from pumping well under the following conditions:

a) Pumping rate 0.028 m3/s

b) Pumping time = 1066 days

c) Drawdown in observation well = 9.52 m

d) Observation well is located 10.0 m from the pumping well

e) Aquifer material = medium sand

f) Aquifer thickness = 14.05 m

Assume that the well is fully penetrating in an unconfined aquifer.