Why Can't I Get Physics Questions Correct?

[sly2289]

I don't understand why I can't get physics questions correct no matter what I do or try I'm never right

 

[Travis_King]

My best advice: Keep track of units. If you know the units you are working with, it is much easier to remember how the equations are ordered. As long as your units cancel (or as long as your answer has the units that make sense) then you are probably ok.

Most of the time people forget terms or add in additional ones and wind up with wrong answers.

 

[Number Nine]

...study more? We really have no idea what kind of trouble you're having.

 

[sly2289]

my troubles consist of not being to apply what i am given, and even if i do that i cannot form an algorithm, if you will, to solve the problem

 

[micromass]

Maybe you can give an example?

A general good advice is to make a lot of problems. Remake the problems you've already solved. Don't just memorize the problem, but think through it. You shouldn't not memorize an awful lot of a physics problem: just the general method.

 

[sly2289]

A space vehicle is traveling at 4980 km/h relative to Earth when the exhausted rocket motor is disengaged and sent backward with a speed of 91 km/h relative to the command module. The mass of the motor is four times the mass of the module. What is the speed (in km/h) of the command module relative to Earth just after the separation?

 

[DaveC426913]

And now show your attempt at solving it...

 

[sly2289]

i've solved it already with assistance but I'm just asking how i can improve when solving them because i never can set up them up in order to solve them

 

[Number Nine]

The problem here is that we really have no idea what problems you're having, other than the fact that you "can't do it". Find a problem that you can't do and show us your attempt at a solution.

 

[jtbell]

Find a problem that you can't do and show us your attempt at a solution.

And do it in the "Introductory Physics" forum in the "Homework and Coursework Questions" section, please.

 

[Chunkysalsa]

It helps to dissolve the problem from words to more of a mathematical statement. When reading the problem record down every variable they give. Draw pictures, especially free-body diagrams whenever you can. Write down variables you don't know yet and attempt to fill in the blanks. The more problems you do, the more of a feel you get towards which variables you need. Read the equations to see how various quantities relate physically.

Also, like Travis said, watch your units. Its a good way to figure out if you made a mistake somewhere.


The only other advice to give is to more and more problems. Do problems where you have access to solutions so you can get a feel for it. The more you do, the more of an intuition you build towards problem solving.