doodiehead
New member
- Mar 24, 2008
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(edit) please pm answers if you need me to verify your answer.
will not verify if they are posted here for the sake of others.
thanks.
QUESTION 1)
bob has 5200$ and needs to build a fence with 4 90*angles ( rect or square )
all the sides have diferent values due to building material etc.
the north wall costs 5$ per foot
the south wall costs 105$ per foot
the east wall costs 15$ per foot
the west wall costs 10$ per foot
bob wants to slend the entire 5200$ and wants to maximize the fenced off area for his cattle.
what is the maximum AREA bob can fence off without going over budget?
ANSWER 1)
some used calculus and one used a parabola formula
the method I used was different.
the greatest area you can get out of a rectangle ( = cost for all sides ) is a square.
so if you spend 1/2 budget on EW walls ( 2600) you can buy 104ft
if you sped 1/2 budget ( 2600 ) on NS walls you can buy 23 7/11 ft.
this combines for a max area of 104 * 23 7/11 = 2458 2/11 or 2458.18181818 ft^2
QUESTION 2) ( playing a tourney on monday so answer on tuesday )
bob builds a water container that is essensially a tube with a flat top and a flat bottom so that he can mount input and output valves on top easily, and so that it will not roll ( due to the flat bottom )
it is 50 meters long and has a diameter of 20 meters ( quite big )
the bottom of the tube is flat with a flat face 6 m wide ( 6m by 50m )
and the top is also flat with a 3m face ( 3m by 50m ).
( when viewed from one end it would look like a circle with the top and bottom cut off and replaced by straight lines. )
100cm = 1m , 2.54cm = 1 inch
what is the volume of bobs tank in ft^3?
( paintshop )
ANSWER 2)
360 - [2*SIN^-1 (1.5/10)] - [2*SIN^-1 (3/10)] = 307.83094
PI*r^2 * 307.83094/360 = 268.63317 = area of both circle segments
area of both triangles = 14.8303 & 28.6182
total volume = 15604.0823m^3
1m = 39.37008 inches = 3.28084 ft
15604.0823* 3.28084^3 = 551 052 ft^3
QUESTION 3)
A moment ( force * perpendicular distance ) occurs about pointF due to the 200N force running from point B to point C
what is the moment about point F?
what is the perpendicular distance from point F to the line of action of the 200N force?
hint for #2: use circle segments ( pi*r^2 * d/360 )
hint for #3: divide the force into Y and Z component forces and use pythagarus with component moments.
use Nmm as a unit, do part a then part b.
answer 3: ( this week )
will not verify if they are posted here for the sake of others.
thanks.
QUESTION 1)
bob has 5200$ and needs to build a fence with 4 90*angles ( rect or square )
all the sides have diferent values due to building material etc.
the north wall costs 5$ per foot
the south wall costs 105$ per foot
the east wall costs 15$ per foot
the west wall costs 10$ per foot
bob wants to slend the entire 5200$ and wants to maximize the fenced off area for his cattle.
what is the maximum AREA bob can fence off without going over budget?
ANSWER 1)
some used calculus and one used a parabola formula
the method I used was different.
the greatest area you can get out of a rectangle ( = cost for all sides ) is a square.
so if you spend 1/2 budget on EW walls ( 2600) you can buy 104ft
if you sped 1/2 budget ( 2600 ) on NS walls you can buy 23 7/11 ft.
this combines for a max area of 104 * 23 7/11 = 2458 2/11 or 2458.18181818 ft^2
QUESTION 2) ( playing a tourney on monday so answer on tuesday )
bob builds a water container that is essensially a tube with a flat top and a flat bottom so that he can mount input and output valves on top easily, and so that it will not roll ( due to the flat bottom )
it is 50 meters long and has a diameter of 20 meters ( quite big )
the bottom of the tube is flat with a flat face 6 m wide ( 6m by 50m )
and the top is also flat with a 3m face ( 3m by 50m ).
( when viewed from one end it would look like a circle with the top and bottom cut off and replaced by straight lines. )
100cm = 1m , 2.54cm = 1 inch
what is the volume of bobs tank in ft^3?
ANSWER 2)
360 - [2*SIN^-1 (1.5/10)] - [2*SIN^-1 (3/10)] = 307.83094
PI*r^2 * 307.83094/360 = 268.63317 = area of both circle segments
area of both triangles = 14.8303 & 28.6182
total volume = 15604.0823m^3
1m = 39.37008 inches = 3.28084 ft
15604.0823* 3.28084^3 = 551 052 ft^3
QUESTION 3)
A moment ( force * perpendicular distance ) occurs about pointF due to the 200N force running from point B to point C
what is the moment about point F?
what is the perpendicular distance from point F to the line of action of the 200N force?
hint for #2: use circle segments ( pi*r^2 * d/360 )
hint for #3: divide the force into Y and Z component forces and use pythagarus with component moments.
use Nmm as a unit, do part a then part b.
answer 3: ( this week )
