Quick Applied Maths Help?

TheBegotten

Could I ask someone to explain the solution to Q4, (b), part (i) for me please? I've looked at it myself and worked it out algebraicly and got a completely different answer, but the questions afterwards are next to impossible to answer without the correct answer for part (i). I'd ask my teacher but we're going over exam tips next week and this is technically last week's work.

Cheers.

B_Rabbit

Which part do you not understand?
All the string has the same tension, T, so there is 2T acting upwards on B. Has mass M so F = MA working downwards F = m(g)

So on the 4g block the tension (T) is acting upwards, and the force downwards F = MA = 4(g).

Same for the other 6kg block, T acting upwards (the string's tension) and F = MA downwards F = 6(g)

Peregrine

Are you sure your link is the right year?

It says show the forces on separate diagrams. There's no real answer to it, just draw three diagrams. How did you do it algebraically?

Nicke011

Is this helpful?
Ask if you don't understand anything
http:/*/prntscr.com/3hefjg
(without *)

TheBegotten

Nimrod 7 wrote: »

Are you sure your link is the right year?

It says show the forces on separate diagrams. There's no real answer to it, just draw three diagrams. How did you do it algebraically?

Oh sorry, Q5 was what I meant. Question four was fine, just a bit of a twist with the m=9.6 bit for part three.

TheBegotten

Nicke011 wrote: »

Is this helpful?
Ask if you don't understand anything
http:/*/prntscr.com/3hefjg
(without *)

That was actually a really good explanation...I hope you didn't go through that trouble on my account

Nicke011

No, you're grand I have most of the questions done in my folder and scanning takes only few seconds
Check this out and tell me if you have problems
http:/*/i.imgur.com/PcbuhLn.jpg

TheBegotten

Nicke011 wrote: »

No, you're grand I have most of the questions done in my folder and scanning takes only few seconds
Check this out and tell me if you have problems
http:/*/i.imgur.com/PcbuhLn.jpg

Oh now I get it you're a life saver, I never thought to solve simultaneously. Thanks a million!

Solid_Shepard

I'm probably going to have been beaten by the time I reply, but just in case:
http:// imgur.com/ucvR6br.jpg (remove the space)
http:// imgur.com/ZR6InbD.jpg (remove the space)

The general format is the same for the majority of these questions; set up before and after, j component not changing, use the Principle of Conservation of Momentum and Newton's Experimental Law of Collisions, simultaneous equations to solve each of the new velocities, find the angle of deflection/use it in some manner, and find the (percentage) loss of Kinetic Energy in which scenario you must use the magnitudes of the velocities before, and the magnitude of the velocities after.

EDIT: I see I was. I guess that's why you don't leave a tab open for awhile before responding :P.

Regarding not seeing that you use Simultaneous Equations, it is a very common method of solving the problems on the course (given that you've a teacher for it I imagine you're doing it in school, and not outside of it, so presumably you know this, but just in case) so it's definitely something to be open to. Question 1, Question 3, Question 4, and Question 5 are but a few areas where you'll run into it very often so if you're ever unsure where to go, definitely look out for an opportunity to lower the amount of variables to one (ie so there's there's only the unknown that you want) so that you can solve the equation. In some places, such as Question 1, this is easier said than done, but Question 3, 4, and 5 in particular are much more stable with regards to the method of solving the question.

TheBegotten

Solid_Shepard wrote: »

Regarding not seeing that you use Simultaneous Equations, it is a very common method of solving the problems on the course (given that you've a teacher for it I imagine you're doing it in school, and not outside of it, so presumably you know this, but just in case) so it's definitely something to be open to. Question 1, Question 3, Question 4, and Question 5 are but a few areas where you'll run into it very often so if you're ever unsure where to go, definitely look out for an opportunity to lower the amount of variables to one (ie so there's there's only the unknown that you want) so that you can solve the equation. In some places, such as Question 1, this is easier said than done, but Question 3, 4, and 5 in particular are much more stable with regards to the method of solving the question.

Sound anyways. I'm doing it after school on a monday, the three local schools form a class of about 12. I'm normally good with simultaneous equations, I just completely forgot about it there. I normally find substitution quicker, but sometimes (such as here) it ends up a lot more complicated than simply solving simultaneously. I'll have to keep it in mind going forwards. I suppose I'm much more used to seeing them in Q4 rather than Q5 as well.

Huell

Here lads what questions are you doing?
I have only covered 1,2,3,4,5,8 and considering covering 10 this weekend

Nicke011

Huell wrote: »

Here lads what questions are you doing?
I have only covered 1,2,3,4,5,8 and considering covering 10 this weekend

Look up this topic www*.boards.ie/v*bulletin/showthread.*php?t=*2057204271
Post there if you're interested