Need help with math HWK!!!
01-13-2009, 02:01 PM
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Need help with math HWK!!!
Hi all,
I was wondering if there were any math majors or anyone with experience in college-level engineering calculus. I'm having some problems with anti derivatives and various related calculations. So if anyone can help me that'll be great! Let me know
I was wondering if there were any math majors or anyone with experience in college-level engineering calculus. I'm having some problems with anti derivatives and various related calculations. So if anyone can help me that'll be great! Let me know
01-13-2009, 02:29 PM
#2
oh boy... engineering calculus... I hated those days... 
I do have my old calculus book with solution manual. great for practicing problems and check your answers. LMK if you want them...
I do have my old calculus book with solution manual. great for practicing problems and check your answers. LMK if you want them...
01-13-2009, 02:40 PM
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01-13-2009, 04:10 PM
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OK, here's one of many problems... I'll post more a little later
A high-speed bullet train accelerates and decelerates at the rate of 4 ft/s2. Its maximum cruising speed is 90 mi/h. (Give your answers correct to one decimal place.)
(a) What is the maximum distance the train can travel if it accelerates from rest until it reaches its cruising speed and then runs at that speed for 15 minutes?
(for a. I calculated that 90mph is 1.5 feet per hour so I just multiplied times 15 and it was still incorrect)
(b) Suppose that the train starts from rest and must come to a complete stop in 15 minutes. What is the maximum distance it can travel under these conditions?
(couldn't get this one)
(c) Find the minimum time that the train takes to travel between two consecutive stations that are 45 miles apart.
(Same thing as a. I used 1.5 feet per mile and multiplied by 45 miles)
(d) The trip from one station to the next takes 37.5 minutes. How far apart are the stations?
A high-speed bullet train accelerates and decelerates at the rate of 4 ft/s2. Its maximum cruising speed is 90 mi/h. (Give your answers correct to one decimal place.)
(a) What is the maximum distance the train can travel if it accelerates from rest until it reaches its cruising speed and then runs at that speed for 15 minutes?
(for a. I calculated that 90mph is 1.5 feet per hour so I just multiplied times 15 and it was still incorrect)
(b) Suppose that the train starts from rest and must come to a complete stop in 15 minutes. What is the maximum distance it can travel under these conditions?
(couldn't get this one)
(c) Find the minimum time that the train takes to travel between two consecutive stations that are 45 miles apart.
(Same thing as a. I used 1.5 feet per mile and multiplied by 45 miles)
(d) The trip from one station to the next takes 37.5 minutes. How far apart are the stations?
01-13-2009, 04:13 PM
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Two ***** are thrown upward from the edge of a cliff 432 ft above the ground. The first is thrown with a speed of 48 ft/s and the other is thrown a second later with a speed of 24 ft/s.
(a) Do the ***** ever pass each other?
1
yes
no
(apparently they do pass each other because if ball A goes up and eventually falls, then the second ball will continue to go up and thus pass each other, but calculating when is the tricky part for me)
(b) If they pass each other, give the time when this occurs. If they do not pass each other, enter NONE.
(a) Do the ***** ever pass each other?
1
yes
no
(apparently they do pass each other because if ball A goes up and eventually falls, then the second ball will continue to go up and thus pass each other, but calculating when is the tricky part for me)
(b) If they pass each other, give the time when this occurs. If they do not pass each other, enter NONE.
01-13-2009, 04:14 PM
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Find f. (x>0)
f ''(x) = x-2
x > 0
f(1) = 0
f(5) = 0
(So for this one, do you have to find the anti derivative twice? and then calculate?)
f ''(x) = x-2
x > 0
f(1) = 0
f(5) = 0
(So for this one, do you have to find the anti derivative twice? and then calculate?)
01-13-2009, 04:16 PM
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Find f.
f '(x) = √x(6 + 10x)
f(1) = 10
(So for this one I really don't get, I initially get the answer "2", but it says its wrong, I get the antiderivative to be 4x^3/2 (x+1). And I plug 1 in for x and set it equal to 10. I get 4x1x2 which equals 8 and subtract 10 from 8 and you get 2
f '(x) = √x(6 + 10x)
f(1) = 10
(So for this one I really don't get, I initially get the answer "2", but it says its wrong, I get the antiderivative to be 4x^3/2 (x+1). And I plug 1 in for x and set it equal to 10. I get 4x1x2 which equals 8 and subtract 10 from 8 and you get 2