Mathematics: Post your doubts here!

[Kirabo Takirambudde]

Of course, the ms will never go through the trouble of solving the questions completely. They'll only write the essential part that'll lead to the answer.

Here are the answers :

wow, just when i thought i was lost with trig, hahaha, u really r a life saver.
Thanks

 

[JulyMei]

Can I know how to find the PE gain?
Why the height is (AB/20)??? I don't get this step..

Question:


Answer:

 

[parthrocks]

anyone plz help me with this:-
http://www.xtremepapers.com/community/attachments/untitled-png.16447/
whitecorp
leadingguy
smzimran
as soon as possiblle

 

[Minato112]

wow, just when i thought i was lost with trig, hahaha, u really r a life saver.
Thanks

No Prob!

 

[Silver Wing]

Can I know how to find the PE gain?
Why the height is (AB/20)??? I don't get this step..

Question:
View attachment 16611

Answer:
View attachment 16612

Firstly you should consider the work rule ,i.e. WD = gain in PE - loss in KE + WD against resistance
After that substitute given information: loss in KE = 0.5 * 16000 * (15^2-12^2)
Gain in PE = mgh = 160000h (h is the VERTICAL height of B above A)
WD against resistance = 1240s (s is the distance AB)
therefore, 1200000 = 160000h - 648000 + 1240s
Furthermore, consider the right angled triangle with sides 1 and hyptenous of 20 where 1 is opposite to theta.
Now if you imagined that triangle on the slope, concluding the h=1 and s=20
remember that this is a ratio, so h/s = 1/20
rearrange ratio to subject h (h=s/20) (this is the subject of your question)
Moreover, Substitute this later equation into your work rule and you will get distance (s) = 200 m

Hope I have helped you,

 

[AhShun]

anyone plz help me with this:-
http://www.xtremepapers.com/community/attachments/untitled-png.16447/
whitecorp
leadingguy
smzimran
as soon as possiblle

 

[Albert Einstein]

Hi help me with the last part the answer is 0.5m

 

[Wanzi21]

can someone explain me on work-energy principle??
i tend to get confuse..
for eg.. one question needs to use K.E - P.E = W.d - W.d against resistance
theres also other question using P.E - K.E = W.d - W.d against resistance
thats different
pls help

 

[Asad Bin Saeed]

can someone explain me on work-energy principle??
i tend to get confuse..
for eg.. one question needs to use K.E - P.E = W.d - W.d against resistance
theres also other question using P.E - K.E = W.d - W.d against resistance
thats different
pls help

I know this difference but i'm confused with W.D against friction part. Plz anyone out there clear this formula for work Energy.

 

[iKhaled]

I know this difference but i'm confused with W.D against friction part. Plz anyone out there clear this formula for work Energy.

W.D - WDr = KE + PE

thats the formula..thats it! KE gets a negative value if its kinetic energy loss and it gets a positive value if its kinetic energy gain and some goes to the PE..

 

[iKhaled]

can someone explain me on work-energy principle??
i tend to get confuse..
for eg.. one question needs to use K.E - P.E = W.d - W.d against resistance
theres also other question using P.E - K.E = W.d - W.d against resistance
thats different
pls help

W.D - WDr = KE + PE

thats the formula..thats it! KE gets a negative value if its kinetic energy loss and it gets a positive value if its kinetic energy gain and some goes to the PE..

 

[Wanzi21]

W.D - WDr = KE + PE

thats the formula..thats it! KE gets a negative value if its kinetic energy loss and it gets a positive value if its kinetic energy gain and some goes to the PE..

I tried that and wow! you are a lifesaver

 

[iKhaled]

I tried that and wow! you are a lifesaver

np mate..i am glad it helped u

 

[parthrocks]

help me whitecorp
minato112

 

[Wanzi21]

np mate..i am glad it helped u

ohh im forget to say thank you!!

 

[JulyMei]

Gonna have my mechanics paper tomorrow. wish me luck. hahaha.. Good luck to others too!

 

[panda222]

help me whitecorp
minato112
View attachment 16718 View attachment 16718

Both of these questions?

 

[shanky631]

Plz whitecorp solve this question.

 

[Taiyaba]

How to find the equation of a line if the gradient is undefined?

And when gradient is not given like in this question:
(5,-3), 2x=3

Please help!

 

[Adhiraj Shinde]

hey a serious doubt.
Oct/Nov 2011 P-32 Q10.
how do u find out the greatest value of the argument.
i am not able to comprehend the question according to the diagram that i have drawn.