equation solver and time restraint in the exam

[Calixico]

If given this problem in an exam, what is the fastest way to solve it if the measly old Casio cannot handle equation like these.

CERM practice problem book#1 for open channel problems.

3 (ft^3/sec)= (1.49/0.012) *2d *(d/d+1)^(2/3) * sqrt(0.01)

this equation simplified to 0.042=[ (d)^(5/3)/(d+1)]..per the solution guide in the text.

Been out of school for a while has this problem hurting my head. I just cannot come up with the book solution of d= 0.314 ft

My casio cannot handle problems like this one so I am wondering if the HP calculator that's allowed in the exam can solve these types of problems. Oh man I miss my TI-89 calculator.

 

[IlPadrino]

If given this problem in an exam, what is the fastest way to solve it if the measly old Casio cannot handle equation like these.
CERM practice problem book#1 for open channel problems.

3 (ft^3/sec)= (1.49/0.012) *2d *(d/d+1)^(2/3) * sqrt(0.01)

this equation simplified to 0.042=[ (d)^(5/3)/(d+1)]..per the solution guide in the text.

Been out of school for a while has this problem hurting my head. I just cannot come up with the book solution of d= 0.314 ft

My casio cannot handle problems like this one so I am wondering if the HP calculator that's allowed in the exam can solve these types of problems. Oh man I miss my TI-89 calculator.

Either I don't understand your notation on the simplified equation or there's a mistake... the first equation is true for d=0.314, the second is not.

Anyway, listen carefully! You are *never* required to solve a problem on the PE exam... you only have to pick the right answer out of four choices. I'm sure you'd agree you could try each of the possible answers given in less than a minute - so don't worry about solving.

 

[EM_PS]

If given this problem in an exam, what is the fastest way to solve it if the measly old Casio cannot handle equation like these.
CERM practice problem book#1 for open channel problems.

3 (ft^3/sec)= (1.49/0.012) *2d *(d/d+1)^(2/3) * sqrt(0.01)

this equation simplified to 0.042=[ (d)^(5/3)/(d+1)]..per the solution guide in the text.

Been out of school for a while has this problem hurting my head. I just cannot come up with the book solution of d= 0.314 ft

My casio cannot handle problems like this one so I am wondering if the HP calculator that's allowed in the exam can solve these types of problems. Oh man I miss my TI-89 calculator.

My casio fx115es solved it (the first equation that is) in approx 10 sec; d = 0.3138083929 anyways. (bout a minute to type in equation though). I'm quite sure the MS115 would have no problem solving it either. . .i suspect your problem is more in your equation input. you could also plug in the given answers using the 'calc' mode after entering (correctly!) the same equation if the 'solve' feature seems to be too problematic for you, but again i think you're not inputting the equation correctly in which case neither mode would work. If you can correctly use a solver on your ti-89 for this equation, you should be able to on the Casio, either model.

 

[Calixico]

My casio fx115es solved it (the first equation that is) in approx 10 sec; d = 0.3138083929 anyways. (bout a minute to type in equation though). I'm quite sure the MS115 would have no problem solving it either. . .i suspect your problem is more in your equation input. you could also plug in the given answers using the 'calc' mode after entering (correctly!) the same equation if the 'solve' feature seems to be too problematic for you, but again i think you're not inputting the equation correctly in which case neither mode would work. If you can correctly use a solver on your ti-89 for this equation, you should be able to on the Casio, either model.

Thanks error matrix and sraymon. Great advice to back-calculate in order to quickly see if equations are true..I finally pulled out the manual for my Casio and realized that it's not that tedious to use afterall. It's just comforting and have the re-assurance that someone else can actually use it to solve equations, which strenghen my will to actually learn the concepts...At firt after using my TI at work it appear primitive to use. But better late than never....Again Kudos!

 

[Dleg]

Either I don't understand your notation on the simplified equation or there's a mistake... the first equation is true for d=0.314, the second is not.
Anyway, listen carefully! You are *never* required to solve a problem on the PE exam... you only have to pick the right answer out of four choices. I'm sure you'd agree you could try each of the possible answers given in less than a minute - so don't worry about solving.

That was exactly what I was going to say - just plug the answers in and back-calculate until you find the answer that works.

However, practice using the problem solver, just so you can do it quickly. But only just to cover all bases. I never used the feature on my Casio in practice. Too slow.